Records |
Author |
Felipe Montiel, N.; Parrilla, M.; Beltrán, V.; Nuyts, G.; Van Durme, F.; De Wael, K. |
Title |
The opportunity of 6-monoacetylmorphine to selectively detect heroin at preanodized screen printed electrodes |
Type |
A1 Journal Article |
Year |
2021 |
Publication |
Talanta |
Abbreviated Journal |
Talanta |
Volume |
|
Issue |
|
Pages |
122005 |
Keywords |
A1 Journal Article; Antwerp X-ray Analysis, Electrochemistry and Speciation (AXES) ; |
Abstract |
The illicit consumption of heroin is an increasing concern in our society. For this reason, rapid analytical methods to seize heroin samples in the field are of paramount importance to hinder drug trafficking, and thus prevent the availability of heroin in the drug market. The present work reports on the enriched electrochemical fingerprint of heroin, allowing its selective detection in street samples, based on the use of electrochemical pretreated screen printed electrodes (p-SPE). The voltammetric identification is built on two oxidation peaks of both heroin and its degradation product 6-monoacetylmorphine (6-MAM), generated in alkaline conditions. Interestingly, an anodic pretreatment of the screen printed electrodes (SPE) shifts the peak potential of paracetamol (the most encountered cutting agent in heroin seizures), allowing the detection of 6-MAM peak, overlapping with the paracetamol signal in the case of untreated SPE. Subsequently, the characterization of the p-SPE with scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, Raman and Fourier transform infrared (FTIR) spectroscopy is provided to demonstrate local changes on the surface of the electrode. From an analytical perspective, p-SPE provide higher sensitivity (0.019 μA μM-1), excellent reproducibility (6-MAM, RSD = 2.85%, and heroin RSD = 0.91%, n = 5) and lower limits of detection (LOD) (5.2 μM) in comparison to untreated SPE. The proposed protocol which integrates a tailor-made script is interrogated against common cutting agents, and finally, validated with the screening of 14 street samples, also analyzed by standard methods. Besides, a comparison with portable spectroscopic techniques on the confiscated samples shows the better performance of the electrochemical strategy. Overall, this sensing approach offers promising results for the rapid on-site profiling of suspicious heroin samples, also in the presence of paracetamol. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000656959000033 |
Publication Date |
2021-01-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0039-9140 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.162 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 833787, BorderSens. The authors acknowledge financial support from the University of Antwerp (IOF). |
Approved |
Most recent IF: 4.162 |
Call Number |
AXES @ axes @c:irua:174844 |
Serial |
6663 |
Permanent link to this record |
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Author |
Van Echelpoel, R.; de Jong, M.; Daems, D.; van Espen, P.; De Wael, K. |
Title |
Unlocking the full potential of voltammetric data analysis : a novel peak recognition approach for (bio)analytical applications |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Talanta |
Abbreviated Journal |
Talanta |
Volume |
233 |
Issue |
|
Pages |
122605 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Bridging the gap between complex signal data output and clear interpretation by non-expert end-users is a major challenge many scientists face when converting their scientific technology into a real-life application. Currently, pattern recognition algorithms are the most frequently encountered signal data interpretation algorithms to close this gap, not in the least because of their straight-forward implementation via convenient software packages. Paradoxically, just because their implementation is so straight-forward, it becomes cumbersome to integrate the expert's domain-specific knowledge. In this work, a novel signal data interpretation approach is presented that uses this domain-specific knowledge as its fundament, thereby fully exploiting the unique expertise of the scientist. The new approach applies data preprocessing in an innovative way that transcends its usual purpose and is easy to translate into a software application. Multiple case studies illustrate the straight-forward application of the novel approach. Ultimately, the approach is highly suited for integration in various (bio)analytical applications that require interpretation of signal data. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000668000500108 |
Publication Date |
2021-06-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0039-9140; 1873-3573 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.162 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 4.162 |
Call Number |
UA @ admin @ c:irua:179417 |
Serial |
8712 |
Permanent link to this record |
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Author |
Parrilla, M.; Detamornrat, U.; Domínguez-Robles, J.; Donnelly, R.F.; De Wael, K. |
Title |
Wearable hollow microneedle sensing patches for the transdermal electrochemical monitoring of glucose |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Talanta : the international journal of pure and applied analytical chemistry |
Abbreviated Journal |
|
Volume |
249 |
Issue |
|
Pages |
123695-123699 |
Keywords |
A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
According to the World Health Organization, about 422 million people worldwide have diabetes, with 1.5 million deaths directly attributed each year. Therefore, there is still a need to effectively monitor glucose in diabetic patients for proper management. Recently, wearable patches based on microneedle (MN) sensors provide minimally invasive analysis of glucose through the interstitial fluid (ISF) while exhibiting excellent correlation with blood glucose. Despite many advances in wearable electrochemical sensors, long-term stability and continuous monitoring remain unsolved challenges. Herein, we present a highly stable electrochemical biosensor based on a redox mediator bilayer consisting of Prussian blue and iron-nickel hexacyanoferrate to increase the long-term stability of the readout coupled with a hollow MN array as a sampling unit for ISF uptake. First, the enzymatic biosensor is developed by using affordable screen-printed electrodes (SPE) and optimized for long-term stability fitting the physiological range of glucose in ISF (i.e., 2.5–22.5 mM). In parallel, the MN array is assessed for minimally invasive piercing of the skin. Subsequently, the biosensor is integrated with the MN array leaving a microfluidic spacer that works as the electrochemical cell. Interestingly, a microfluidic channel connects the cell with an external syringe to actively and rapidly withdraw ISF toward the cell. Finally, the robust MN sensing patch is characterized during in vitro and ex vivo tests. Overall, affordable wearable MN-based patches for the continuous monitoring of glucose in ISF are providing an advent in wearable devices for rapid and life-threatening decision-making processes. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000826441800002 |
Publication Date |
2022-06-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0039-9140; 1873-3573 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:188955 |
Serial |
8955 |
Permanent link to this record |
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Author |
Daems, E.; Moro, G.; Campos, R.; De Wael, K. |
Title |
Mapping the gaps in chemical analysis for the characterisation of aptamer-target interactions |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Trac-Trends In Analytical Chemistry |
Abbreviated Journal |
Trac-Trend Anal Chem |
Volume |
142 |
Issue |
|
Pages |
116311 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Aptamers are promising biorecognition elements with a wide applicability from therapeutics to bio-sensing. However, to successfully use these biomolecules, a complete characterisation of their bindingperformance in the presence of the target is crucial. Several multi-analytical approaches have been re-ported including techniques to describe kinetic and thermodynamic aspects of the aptamer-targetinteraction, and techniques which allow an in-depth understanding of the aptamer-target structures.Recent literature shows the need of a critical data interpretation, a combination of characterisationtechniques and suggests the key role of the characterisation protocol design. Indeed, thefinal applicationof the aptamer should be considered before choosing the characterisation method. All the limitations andcapabilities of the analytical tools in use for aptamer characterisation should be taken into account. Here,we present a critical overview of the current methods and multi-analytical approaches to study aptamer-target binding, aiming to provide researchers with guidelines for the design of characterisation protocols. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000682179000010 |
Publication Date |
2021-04-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0165-9936; 1879-3142 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.442 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 8.442 |
Call Number |
UA @ admin @ c:irua:179407 |
Serial |
8203 |
Permanent link to this record |
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Author |
Drăgan, A.-M.; Parrilla, M.; Feier, B.; Oprean, R.; Cristea, C.; De Wael, K. |
Title |
Analytical techniques for the detection of amphetamine-type substances in different matrices : a comprehensive review |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Trac-Trends In Analytical Chemistry |
Abbreviated Journal |
Trac-Trend Anal Chem |
Volume |
145 |
Issue |
|
Pages |
116447 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
This current review focuses on contributions to amphetamine-type substances (ATS) analysis. This type of synthetic illicit drugs has been increasingly present worldwide reaching 5% of the market on illicit drugs in 2019. The increment of their production in many clandestine laboratories and easy distribution among society are two of the main concerns towards the battle against synthetic drugs. Therefore, the first part of this review details the classification and mechanism of action of ATS in the human body. Second, the pharmacological and toxicological effects of ATS on human health are described to motivate the need of early detection of ATS. Subsequently, the most used laboratory-based and portable methods are presented and critically discussed along the review. Finally, a careful discussion on the advantages and disadvantages of portable techniques employed on the field are addressed as potential tools for on-site ATS detection by law enforcement officers. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000723747000009 |
Publication Date |
2021-09-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0165-9936; 1879-3142 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.442 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 8.442 |
Call Number |
UA @ admin @ c:irua:183268 |
Serial |
7460 |
Permanent link to this record |
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Author |
Muhammad, S.; Wuyts, K.; Nuyts, G.; De Wael, K.; Samson, R. |
Title |
Characterization of epicuticular wax structures on leaves of urban plant species and its association with leaf wettability |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Urban Forestry & Urban Greening |
Abbreviated Journal |
Urban For Urban Gree |
Volume |
47 |
Issue |
47 |
Pages |
126557 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Epicuticular wax (EW) protects the plant’s integrity and acts as a barrier against biotic and abiotic stresses. The micro-structured three-dimensional EW’s and presence of leaf trichomes influence the wettability of a leaf surface. In this study, leaves of 96 perennial urban plant species were examined to determine an association between epicuticular wax structure (EWS) types and leaf wettability and investigate their seasonal variation. The EWS types were identified using Scanning Electron Microscopy (SEM), while leaf wettability was analyzed by measuring the drop contact angle (DCA) on both the abaxial and the adaxial sides of leaves collected from a common garden in June and September 2016. Four distinct EWS types namely thin film, platelets, crusts, and tubules were observed on leaves of investigated plant species in both June and September. The EWS types varied significantly between functional plant types and plant families in both June and September. In June, the abaxial DCA ranged from 56° to 147°, and the adaxial DCA ranged from 56° to 136°. In September, the abaxial DCA ranged from 54° to 130°, and the adaxial DCA ranged from 51° to 125°. The effect of time, leaf side, and EWS type on leaf wettability were significant. Plant species which showed a change in EWS type or clustering from June to September did not show a more pronounced reduction in DCA compared to those species which exhibited a constant EWS type. Findings from our study illustrate that DCA is not a good indicator in determining the different EWS types due to overlapping DCA intervals between the identified EWS types. However, the identified EWS types remained fairly stable throughout the in-leaf season and do not require repeated measurements for characterization. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000508389000028 |
Publication Date |
2019-12-05 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1618-8667 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.4 |
Times cited |
5 |
Open Access |
|
Notes |
; The research was funded by the Ontario Student Assistance Program (OSAP # 15103399). The SEM equipment was funded by FWO/Hercules. The authors acknowledge the help of the ENdEMIC group involved in the upkeep of the experimental site. The authors would like to thank the anonymous reviewers for their critical comments and constructive suggestions in improving the quality of the article. ; |
Approved |
Most recent IF: 6.4; 2020 IF: 2.113 |
Call Number |
UA @ admin @ c:irua:164906 |
Serial |
5504 |
Permanent link to this record |
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Author |
Neven, L.; Thiruvottriyur Shanmugam, S.; Rahemi, V.; Trashin, S.; Sleegers, N.; Carrion, E.N.; Gorun, S.M.; De Wael, K. |
Title |
Optimized photoelectrochemical detection of essential drugs bearing phenolic groups |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
91 |
Issue |
15 |
Pages |
9962-9969 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
The World Health Organization (WHO) model “List of Essential Medicines” includes among indispensable medicines antibacterials and pain and migraine relievers. Monitoring their concentration in the environment, while challenging, is important in the context of antibiotic resistance as well as their production of highly toxic compounds via hydrolysis. Traditional detection methods such as high-performance liquid chromatography (HPLC) or LC combined with tandem mass spectrometry or UV-vis spectroscopy are time-consuming, have a high cost, require skilled operators and are difficult to adapt for field operations. In contrast, (electrochemical) sensors have elicited interest because of their rapid response, high selectivity, and sensitivity as well as potential for on-site detection. Previously, we reported a novel sensor system based on a type II photosensitizer, which combines the advantages of enzymatic sensors (high sensitivity) and photoelectrochemical sensors (easy baseline subtraction). Under red-light illumination, the photosensitizer produces singlet oxygen which oxidizes phenolic compounds present in the sample. The subsequent reduction of the oxidized phenolic compounds at the electrode surface gives rise to a quantifiable photocurrent and leads to the generation of a redox cycle. Herein we report the optimization in terms of pH and applied potential of the photoelectrochemical detection of the hydrolysis product of paracetamol, i.e., 4-aminophenol (4-AP), and two antibacterials, namely, cefadroxil (CFD, beta-lactam antibiotic) and doxycycline (DXC, tetracycline antibiotic). The optimized conditions resulted in a detection limit of 0.2 mu mol L-1 for DXC, but in a 10 times higher sensitivity, 20 nmol L-1, for CFD. An even higher sensitivity, 7 nmol L-1, was noted for 4-AP. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000480499200086 |
Publication Date |
2019-06-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
2 |
Open Access |
|
Notes |
; FWO and UA-BOF are acknowledged for financial support. The Center for Functional Materials of Seton Hall University is thanked for support (S.M.G. and E.N.C.). Joren Van Loon is thanked for the graphical abstract. This research was supported by the medium scale research infrastructure funding Hercules funding (SEM). ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:161831 |
Serial |
5763 |
Permanent link to this record |
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Author |
Hamidi-Asl, E.; Daems, D.; De Wael, K.; Van Camp, G.; Nagels, L.J. |
Title |
Concentration related response potentiometric titrations to study the interaction of small molecules with large biomolecules |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
86 |
Issue |
24 |
Pages |
12243-12249 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
In the present article, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small molecule interactions is reported. This approach is fast, sensitive, reproducible and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed to a concentration related signal over the entire concentration interval, also at low concentrations, where the mV (y-axis) versus logcanalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, the Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anti-cocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis (4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using SPR. The potentiometric titration approach called Concentration related Response Potentiometry, is used to study molecular interaction for 7 macromolecular target molecules and 4 small molecule ligands. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000346683900048 |
Publication Date |
2014-11-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
10 |
Open Access |
|
Notes |
; Financial support for this work was provided by the University of Antwerp by granting L.J.N., K.D.W, G.V.C., and Ronny Blust a POC interdisciplinary research project. ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
Call Number |
UA @ admin @ c:irua:120164 |
Serial |
5548 |
Permanent link to this record |
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Author |
Trashin, S.; Morales-Yánez, F.; Thiruvottriyur Shanmugam, S.; Paredis, L.; Carrión, E.N.; Sariego, I.; Muyldermans, S.; Polman, K.; Gorun, S.M.; De Wael, K. |
Title |
Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
93 |
Issue |
40 |
Pages |
13606-13614 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
Detection of antigenic biomarkers present in trace amounts is of crucial importance for medical diagnosis. A parasitic disease, human toxocariasis, lacks an adequate diagnostic method despite its worldwide occurrence. The currently used serology tests may stay positive even years after a possibly unnoticed infection, whereas the direct detection of a re-infection or a still active infection remains a diagnostic challenge due to the low concentration of circulating parasitic antigens. We report a time-efficient sandwich immunosensor using small recombinant single-domain antibodies (nanobodies) derived from camelid heavy-chain antibodies specific to Toxocara canis antigens. An enhanced sensitivity to pg/mL levels is achieved by using a redox cycle consisting of a photocatalytic oxidation and electrochemical reduction steps. The photocatalytic oxidation is achieved by a photosensitizer generating singlet oxygen (1O2) that, in turn, readily reacts with p-nitrophenol enzymatically produced under alkaline conditions. The photooxidation produces benzoquinone that is electrochemically reduced to hydroquinone, generating an amperometric response. The light-driven process could be easily separated from the background, thus making amperometric detection more reliable. The proposed method for detection of the toxocariasis antigen marker shows superior performances compared to other detection schemes with the same nanobodies and outperforms by at least two orders of magnitude the assays based on regular antibodies, thus suggesting new opportunities for electrochemical immunoassays of challenging low levels of antigens. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000708550500025 |
Publication Date |
2021-09-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:181795 |
Serial |
8290 |
Permanent link to this record |
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Author |
Neven, L.; Barich, H.; Ching, H.Y.V.; Khan, S.U.; Colomier, C.; Patel, H.H.; Gorun, S.M.; Verbruggen, S.; Van Doorslaer, S.; De Wael, K. |
Title |
Correlation between the fluorination degree of perfluorinated zinc phthalocyanines, their singlet oxygen generation ability, and their photoelectrochemical response for phenol sensing |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
94 |
Issue |
13 |
Pages |
5221-5230 |
Keywords |
A1 Journal article; Organic synthesis (ORSY); Sustainable Energy, Air and Water Technology (DuEL); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
Electron-withdrawing perfluoroalkyl peripheral groups grafted on phthalocyanine (Pc) macrocycles improve their single-site isolation, solubility, and resistance to self-oxidation, all beneficial features for catalytic applications. A high degree of fluorination also enhances the reducibility of Pcs and could alter their singlet oxygen (1O2) photoproduction. The ethanol/toluene 20:80 vol % solvent mixture was found to dissolve perfluorinated FnPcZn complexes, n = 16, 52, and 64, and minimize the aggregation of the sterically unencumbered F16PcZn. The 1O2 production ability of FnPcZn complexes was examined using 9,10-dimethylanthracene (DMA) and 2,2,6,6-tetramethylpiperidine (TEMP) in combination with UV–vis and electron paramagnetic resonance (EPR) spectroscopy, respectively. While the photoreduction of F52PcZn and F64PcZn in the presence of redox-active TEMP lowered 1O2 production, DMA was a suitable 1O2 trap for ranking the complexes. The solution reactivity was complemented by solid-state studies via the construction of photoelectrochemical sensors based on TiO2-supported FnPcZn, FnPcZn|TiO2. Phenol photo-oxidation by 1O2, followed by its electrochemical reduction, defines a redox cycle, the 1O2 production having been found to depend on the value of n and structural features of the supported complexes. Consistent with solution studies, F52PcZn was found to be the most efficient 1O2 generator. The insights on reactivity testing and structural–activity relationships obtained may be useful for designing efficient and robust sensors and for other 1O2-related applications of FnPcZn. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000786254500002 |
Publication Date |
2022-03-22 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.4 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 7.4 |
Call Number |
UA @ admin @ c:irua:187522 |
Serial |
7141 |
Permanent link to this record |
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|
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Author |
Khan, S.U.; Trashin, S.; Beltran, V.; Korostei, Y.S.; Pelmus, M.; Gorun, S.M.; Dubinina, T., V.; Verbruggen, S.W.; De Wael, K. |
Title |
Photoelectrochemical behavior of phthalocyanine-sensitized TiO₂ in the presence of electron-shuttling mediators |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
94 |
Issue |
37 |
Pages |
12723-12731 |
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
Dye-sensitized TiO(2 )has found many applications for dye sensitized solar cells (DSSC), solar-to-chemical energy conversion, water/air purification systems, and (electro)chemical sensors. We report an electrochemical system for testing dye-sensitized materials that can be utilized in photoelectrochemical (PEC) sensors and energy conversion. Unlike related systems, the reported system does not require a direct electron transfer from semiconductors to electrodes. Rather, it relies on electron shuttling by redox mediators. A range of model photocatalytic materials were prepared using three different TiO2 materials (P25, P90, and PC500) and three sterically hindered phthalocyanines (Pcs) with electron-rich tert-butyl substituents (t-Bu4PcZn, t-Bu4PcAlCl, and t-Bu4PcH2). The materials were compared with previously developed TiO(2 )modified by electron-deficient, also sterically hindered fluorinated phthalocyanine F64PcZn, a singlet oxygen (O-1(2)) producer, as well as its metal-free derivative, F64PcH2. The PEC activity depended on the redox mediator, as well as the type of TiO2 and Pc. By comparing the responses of one-electron shuttles, such as K4Fe(CN)(4), and O-1(2)-reactive electron shuttles, such as phenol, it is possible to reveal the action mechanism of the supported photosensitizers, while the overall activity can be assessed using hydroquinone. t-Bu4PcAlCl showed significantly lower blank responses and higher specific responses toward chlorophenols compared to t-Bu4PcZn due to the electron-withdrawing effect of the Al3+ metal center. The combination of reactivity insights and the need for only microgram amounts of sensing materials renders the reported system advantageous for practical applications. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000855284300001 |
Publication Date |
2022-09-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.4 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 7.4 |
Call Number |
UA @ admin @ c:irua:190602 |
Serial |
7190 |
Permanent link to this record |
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Author |
Ranjbari, E.; Hadjmohammadi, M.R.; Kiekens, F.; De Wael, K. |
Title |
Mixed hemi/ad-micelle sodium dodecyl sulfate-coated magnetic iron oxide nanoparticles for the efficient removal and trace determination of rhodamine-B and rhodamine-6G |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
87 |
Issue |
15 |
Pages |
7894-7901 |
Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different [SDS]/[MIONP] ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in [SDS]/[MIONP] ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; [SDS]/[MIONP] ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g1, respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L1 of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL1. Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000359277900056 |
Publication Date |
2015-07-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
36 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 6.32; 2015 IF: 5.636 |
Call Number |
UA @ admin @ c:irua:126583 |
Serial |
5730 |
Permanent link to this record |
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Author |
Ayalew, E.; Janssens, K.; De Wael, K. |
Title |
Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
88 |
Issue |
3 |
Pages |
1564-1569 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000369471100014 |
Publication Date |
2015-12-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
9 |
Open Access |
|
Notes |
; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:129963 |
Serial |
5888 |
Permanent link to this record |
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Author |
Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. |
Title |
Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
89 |
Issue |
89 |
Pages |
3326-3334 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000397478300015 |
Publication Date |
2017-02-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0003-2700 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
OpenAccess |
Notes |
; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ lucian @ c:irua:140886 |
Serial |
4451 |
Permanent link to this record |
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Author |
De Jong, M.; Florea, A.; de Vries, A.-M.; van Nuijs, A.L.N.; Covaci, A.; Van Durme, F.; Martins, J.C.; Samyn, N.; De Wael, K. |
Title |
Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
90 |
Issue |
8 |
Pages |
5290-5297 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
Abstract |
The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000430512200049 |
Publication Date |
2018-02-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
8 |
Open Access |
|
Notes |
; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by BR/314/PI/ APTADRU Project and IOF-SBO (UAntwerp). Alexander van Nuijs acknowledges the Research Foundation-Flanders (FWO) for his postdoctoral fellowship. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:149528 |
Serial |
5693 |
Permanent link to this record |
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Author |
De Jong, M.; Florea, A.; Eliaerts, J.; Van Durme, F.; Samyn, N.; De Wael, K. |
Title |
Tackling poor specificity of cocaine color tests by electrochemical strategies |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
90 |
Issue |
11 |
Pages |
6811-6819 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
This paper presents electrochemical strategies for the fast screening of cocaine and most common cutting agents found in seized drug samples. First, a study on the performance of Scott color tests on cocaine and a wide range of cutting agents is described. The cutting agents causing false positive or false negative results when in mixture with cocaine are identified. To overcome the lack of specificity of color tests, we further propose a fast screening strategy by means of square wave voltammetry on disposable graphite screen printed electrodes, which reveals the unique fingerprint of cocaine and cutting agents. By employing a forward and backward scan and by a dual pH strategy, we enrich the electrochemical fingerprint and enable the simultaneous detection of cocaine and cutting agents. The effectiveness of the developed strategies was tested for the detection of cocaine in seized cocaine samples and compared with the color tests. Moreover, we prove the usefulness of square wave voltammetry for predicting possible interfering agents in color tests, based on the reduction peak of cobalt thiocyanate. The developed electrochemical strategies allow for a quick screening of seized cocaine samples resulting in a selective identification of drugs and cutting agents. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000434893200066 |
Publication Date |
2018-05-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
|
Notes |
; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by Grants BR/314 /PI/APTADRU and IOF-SBO. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:151316 |
Serial |
5867 |
Permanent link to this record |
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Author |
Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. |
Title |
Cephalosporin antibiotics : electrochemical fingerprints and core structure reactions investigated by LC-MSMS |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
91 |
Issue |
3 |
Pages |
2035-2041 |
Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
Abstract |
Electrochemistry and exploiting electrochemical fingerprints is a potent approach to address newly emerging surveillance needs, for instance for antibiotics. However, a comprehensive insight in the electrochemical oxidation behaviour and mechanism is re-quired for this sensing strategy. To address the lack in knowledge of the voltammetric behaviour of the cephalosporins antibiotics, a selection of cephalosporin antibiotics and two main intermediates were subjected to an electrochemical study of their redox behaviour by means of pulsed voltammetric techniques and small-scale electrolysis combined with HPLC-MS/MS analyses. Sur-prisingly, the detected oxidation products did not fit the earlier suggested oxidation of the sulfur group to the corresponding sul-foxide. The influence of different side chains, both at the three and the seven position of the β-lactam core structure on the elec-trochemical fingerprint were investigated. Additional oxidation signals at lower potentials were elucidated and linked to different side chains. These signals were further exploited to allow simultaneous detection of different cephalosporins in one voltammetric sweep. These fundamental insights can become the building blocks for an new on-site screening method. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000458220300055 |
Publication Date |
2019-01-03 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
6 |
Open Access |
|
Notes |
; The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:156046 |
Serial |
5497 |
Permanent link to this record |
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Author |
Morales-Yanez, F.; Trashin, S.; Hermy, M.; Sariego, I.; Polman, K.; Muyldermans, S.; De Wael, K. |
Title |
Fast one-step ultrasensitive detection of toxocara canis antigens by a nanobody-based electrochemical magnetosensor |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
91 |
Issue |
18 |
Pages |
11582-11588 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Human toxocariasis (HT) is a cosmopolitan zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis. Current HT diagnostic methods do not discriminate between active and past infections. Here, we present a method to quantify Toxocara excretory/secretory antigen, aiming to identify active cases of HT. High specificity is achieved by employing nanobodies (Nbs), single domain antigen binding fragments from camelid heavy chain-only antibodies. High sensitivity is obtained by the design of an electrochemical magnetosensor with an amperometric read-out. Reliable detection of TES antigen at 10 and 30 pg/mL level was demonstrated in phosphate buffered saline and serum, respectively. Moreover, the assay showed no cross-reactivity with other nematode antigens. To our knowledge, this is the most sensitive method to quantify the TES antigen so far. It also has great potential to develop point of care diagnostic systems in other conditions where high sensitivity and specificity are required. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000487156900016 |
Publication Date |
2019-08-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
2 |
Open Access |
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Notes |
; This project was funded by the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO-Flanders, Project G.0189.13N) and BOF UAntwerp. The authors acknowledge Prof. Pierre Dorny (Institute of Tropical Medicine Antwerp) and Dr. Beatrice Nickel (Swiss Institute of Tropical Medicine) for providing the antigens needed for the cross-reactivity experiments. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:163784 |
Serial |
5621 |
Permanent link to this record |
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Author |
Florea, A.; Schram, J.; De Jong, M.; Eliaerts, J.; Van Durme, F.; Kaur, B.; Samyn, N.; De Wael, K. |
Title |
Electrochemical strategies for adulterated heroin samples |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
91 |
Issue |
12 |
Pages |
7920-7928 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Electrochemical strategies to selectively detect heroin in street samples without the use of complicated electrode modifications were developed for the first time. For this purpose, heroin, mixing agents (adulterants, cutting agent, and impurities), and their binary mixtures were subjected to square wave voltammetry measurements at bare graphite electrodes at pH 7.0 and pH 12.0, in order to elucidate the unique electrochemical fingerprint of heroin and mixing agents as well as possible interferences or reciprocal influences. Adjusting the pH from pH 7.0 to pH 12.0 allowed a more accurate detection of heroin in the presence of most common mixing agents. Furthermore, the benefit of introducing a preconditioning step prior to running square wave voltammetry on the electrochemical fingerprint enrichment was explored. Mixtures of heroin with other drugs (cocaine, 3,4-methylenedioxymethamphetamine, and morphine) were also tested to explore the possibility of their discrimination and simultaneous detection. The feasibility of the proposed electrochemical strategies was tested on realistic heroin street samples from forensic cases, showing promising results for fast, on-site detection tools of drugs of abuse. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000472682000056 |
Publication Date |
2019-05-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
2 |
Open Access |
|
Notes |
; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. The authors also acknowledge IOF (UAntwerp) and Belspo for financial support. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:160061 |
Serial |
5596 |
Permanent link to this record |
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Author |
De Jong, M.; Sleegers, N.; Florea, A.; Van Loon, J.; van Nuijs, A.L.N.; Samyn, N.; De Wael, K. |
Title |
Unraveling the mechanisms behind the complete suppression of cocaine electrochemical signals by chlorpromazine, promethazine, procaine, and dextromethorphan |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
91 |
Issue |
24 |
Pages |
15453-15460 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre; Product development |
Abstract |
The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000503910600018 |
Publication Date |
2019-11-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
|
Open Access |
|
Notes |
; The authors acknowledge financial support from IOF-SBO/POC (UAntwerp) and the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:165727 |
Serial |
5887 |
Permanent link to this record |
|
|
|
Author |
Rahemi, V.; Trashin, S.; Hafideddine, Z.; Van Doorslaer, S.; Meynen, V.; Gorton, L.; De Wael, K. |
Title |
Amperometric flow-injection analysis of phenols induced by reactive oxygen species generated under daylight irradiation of titania impregnated with horseradish peroxidase |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
92 |
Issue |
92 |
Pages |
3643-3649 |
Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Titanium dioxide (TiO2) is a unique material for biosensing applications due to its capability of hosting enzymes. For the first time, we show that TiO2 can accumulate reactive oxygen species (ROS) under daylight irradiation and can support the catalytic cycle of horseradish peroxidase (HRP) without the need of H2O2 to be present in the solution. Phenolic compounds, such as hydroquinone (HQ) and 4-aminophenol (4-AP), were detected amperometrically in flow-injection analysis (FIA) mode via the use of an electrode modified with TiO2 impregnated with HRP. In contrast to the conventional detection scheme, no H2O2 was added to the analyte solution. Basically, the inherited ability of TiO2 to generate reactive oxygen species is used as a strategy to avoid adding H2O2 in the solution during the detection of phenolic compounds. Electron paramagnetic resonance (EPR) spectroscopy indicates the presence of ROS on titania which, in interaction with HRP, initiate the electrocatalysis toward phenolic compounds. The amperometric response to 4-AP was linear in the concentration range between 0.05 and 2 μM. The sensitivity was 0.51 A M–1 cm–2, and the limit of detection (LOD) 26 nM. The proposed sensor design opens new opportunities for the detection of phenolic traces by HRP-based electrochemical biosensors, yet in a more straightforward and sensitive way following green chemistry principles of avoiding the use of reactive and harmful chemical, such as H2O2. |
Address |
|
Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000518234700023 |
Publication Date |
2020-01-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.4 |
Times cited |
3 |
Open Access |
|
Notes |
; The authors thank Scientific Reseatch-Flanders (F-WO) (grant 12T4219N) for funding. ; |
Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
Call Number |
UA @ admin @ c:irua:166241 |
Serial |
5463 |
Permanent link to this record |
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|
|
Author |
Marchetti, A.; Saniz, R.; Krishnan, D.; Rabbachin, L.; Nuyts, G.; De Meyer, S.; Verbeeck, J.; Janssens, K.; Pelosi, C.; Lamoen, D.; Partoens, B.; De Wael, K. |
Title |
Unraveling the Role of Lattice Substitutions on the Stabilization of the Intrinsically Unstable Pb2Sb2O7Pyrochlore: Explaining the Lightfastness of Lead Pyroantimonate Artists’ Pigments |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Chemistry Of Materials |
Abbreviated Journal |
Chem Mater |
Volume |
32 |
Issue |
7 |
Pages |
2863-2873 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
The pyroantimonate pigments Naples yellow and lead tin antimonate yellow are recognized as some of the most stable synthetic yellow pigments in the history of art. However, this exceptional lightfastness is in contrast with experimental evidence suggesting that this class of mixed oxides is of semiconducting nature. In this study the electronic structure and light-induced behavior of the lead pyroantimonate pigments were determined by means of a combined multifaceted analytical and computational approach (photoelectrochemical measurements, UV-vis diffuse reflectance spectroscopy, STEM-EDS, STEM-HAADF, and density functional theory calculations). The results demonstrate both the semiconducting nature and the lightfastness of these pigments. Poor optical absorption and minority carrier mobility are the main properties responsible for the observed stability. In addition, novel fundamental insights into the role played by Na atoms in the stabilization of the otherwise intrinsically unstable Pb2Sb2O7 pyrochlore were obtained. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000526394000016 |
Publication Date |
2020-04-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.6 |
Times cited |
8 |
Open Access |
OpenAccess |
Notes |
Universiteit Antwerpen; Belgian Federal Science Policy Office; |
Approved |
Most recent IF: 8.6; 2020 IF: 9.466 |
Call Number |
EMAT @ emat @c:irua:168819 |
Serial |
6363 |
Permanent link to this record |
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|
Author |
Ehirim, T.J.; Ozoemena, O.C.; Mwonga, P.V.; Haruna, A.B.; Mofokeng, T.P.; De Wael, K.; Ozoemena, K.I. |
Title |
Onion-like carbons provide a favorable electrocatalytic platform for the sensitive detection of tramadol drug |
Type |
A1 Journal article |
Year |
2022 |
Publication |
ACS Omega |
Abbreviated Journal |
|
Volume |
7 |
Issue |
51 |
Pages |
47892-47905 |
Keywords |
A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
This work reports the first study on the possible application of nanodiamond-derived onion-like carbons (OLCs), in comparison with conductive carbon black (CB), as an electrode platform for the electrocatalytic detection of tramadol (an important drug of abuse). The physicochemical properties of OLCs and CB were determined using X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA). The OLC exhibits, among others, higher surface area, more surface defects, and higher thermal stability than CB. From the electrochemical analysis (interrogated using cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy), it is shown that an OLC-modified glassy carbon electrode (GCE-OLC) allows faster electron transport and electrocatalysis toward tramadol compared to a GCE-CB. To establish the underlying science behind the high performance of the OLC, theoretical calculations (density functional theory (DFT) simulations) were conducted. DFT predicts that OLC allows for weaker surface binding of tramadol (Ead = -26.656 eV) and faster kinetic energy (K.E. = -155.815 Ha) than CB (Ead = -40.174 eV and -305.322 Ha). The GCE-OLC shows a linear calibration curve for tramadol over the range of similar to 55 to 392 mu M, with high sensitivity (0.0315 mu A/mu M) and low limit of detection (LoD) and quantification (LoQ) (3.8 and 12.7 mu M, respectively). The OLC-modified screen-printed electrode (SPE-OLC) was successfully applied for the sensitive detection of tramadol in real pharmaceutical formulations and human serum. The OLC-based electrochemical sensor promises to be useful for the sensitive and accurate detection of tramadol in clinics, quality control, and routine quantification of tramadol drugs in pharmaceutical formulations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000903165200001 |
Publication Date |
2022-12-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2470-1343 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:193391 |
Serial |
8908 |
Permanent link to this record |
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|
|
Author |
Blidar, A.; Trashin, S.; Carrion, E.N.; Gorun, S.M.; Cristea, C.; De Wael, K. |
Title |
Enhanced photoelectrochemical detection of an analyte triggered by its concentration by a singlet oxygen-generating fluoro photosensitizer |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Acs Sensors |
Abbreviated Journal |
Acs Sensors |
Volume |
5 |
Issue |
11 |
Pages |
3501-3509 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
The use of a photocatalyst (photosensitizer) which produces singlet oxygen instead of enzymes for oxidizing analytes creates opportunities for designing cost-efficient and sensitive photoelectrochemical sensors. We report that perfluoroisopropyl-substituted zinc phthalocyanine (F64PcZn) interacts specifically with a complex phenolic compound, the antibiotic rifampicin (RIF), but not with hydroquinone or another complex phenolic compound, the antibiotic doxycycline. The specificity is imparted by the selective preconcentration of RIF in the photocatalytic layer, as revealed by electrochemical and optical measurements, complemented by molecular modeling that confirms the important role of a hydrophobic cavity formed by the iso-perfluoropropyl groups of the photocatalyst. The preconcentration effect favorably enhances the RIF photoelectrochemical detection limit as well as sensitivity to nanomolar (ppb) concentrations, LOD = 7 nM (6 ppb) and 2.8 A.M-1.cm(-2), respectively. The selectivity to RIF, retained in the photosensitizer layer, is further enhanced by the selective removal of all unretained phenols via simple washing of the electrodes with pure buffer. The utility of the sensor for analyzing municipal wastewater was demonstrated. This first demonstration of enhanced selectivity and sensitivity due to intrinsic interactions of a molecular photocatalyst (photosensitizer) with an analyte, without use of a biorecognition element, may allow the design of related, robust, simple, and viable sensors. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000595550100021 |
Publication Date |
2020-10-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2379-3694 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.9 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.9; 2020 IF: NA |
Call Number |
UA @ admin @ c:irua:176057 |
Serial |
7913 |
Permanent link to this record |
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|
Author |
Parrilla, M.; Detamornrat, U.; Domínguez-Robles, J.; Tunca, S.; Donnelly, R.F.; De Wael, K. |
Title |
Wearable microneedle-based array patches for continuous electrochemical monitoring and drug delivery : toward a closed-loop system for methotrexate treatment |
Type |
A1 Journal article |
Year |
2023 |
Publication |
ACS sensors |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
acssensors.3c01381-10 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
Wearable devices based on microneedle (MN) technology have recently emerged as tools for in situ transdermal sensing or delivery in interstitial fluid (ISF). Particularly, MN-based electrochemical sensors allow the continuous monitoring of analytes in a minimally invasive manner through ISF. Exogenous small molecules found in ISF such as therapeutic drugs are ideal candidates for MN sensors due to their correlation with blood levels and their relevance for the optimal management of personalized therapies. Herein, a hollow MN array patch is modified with conductive pastes and functionalized with cross-linked chitosan to develop an MN-based voltammetric sensor for continuous monitoring of methotrexate (MTX). Interestingly, the chitosan coating avoids biofouling while enabling the adsorption of MTX at the electrode’s surface for sensitive analysis. The MN sensor exhibits excellent analytical performance in vitro with protein-enriched artificial ISF and ex vivo under a Franz diffusion cell configuration. The MN sensor shows a linear range from 25 to 400 μM, which fits within the therapeutic range of high-dose MTX treatment for cancer patients and an excellent continuous operation for more than two days. Moreover, an iontophoretic hollow MN array patch is developed with the integration of both the anode and cathode in the single MN array patch. The ex vivo characterization demonstrates the transdermal on-demand drug delivery of MTX. Overall, the combination of both MN patches represents impactful progress in closed-loop systems for therapeutic drug management in disorders such as cancer, rheumatoid arthritis, or psoriasis. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001109702900001 |
Publication Date |
2023-10-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2379-3694 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.9 |
Times cited |
|
Open Access |
Not_Open_Access: Available from 19.04.2024 |
Notes |
|
Approved |
Most recent IF: 8.9; 2023 IF: NA |
Call Number |
UA @ admin @ c:irua:200074 |
Serial |
8956 |
Permanent link to this record |
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|
|
Author |
Trashin, S.; Rahemi, V.; Ramji, K.; Neven, L.; Gorun, S.M.; De Wael, K. |
Title |
Singlet oxygen-based electrosensing by molecular photosensitizers |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
|
Pages |
16108 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Enzyme-based electrochemical biosensors are an inspiration for the development of (bio)analytical techniques. However, the instability and reproducibility of the reactivity of enzymes, combined with the need for chemical reagents for sensing remain challenges for the construction of useful devices. Here we present a sensing strategy inspired by the advantages of enzymes and photoelectrochemical sensing, namely the integration of aerobic photocatalysis and electrochemical analysis. The photosensitizer, a bioinspired perfluorinated Zn phthalocyanine, generates singlet-oxygen from air under visible light illumination and oxidizes analytes, yielding electrochemically-detectable products while resisting the oxidizing species it produces. Compared with enzymatic detection methods, the proposed strategy uses air instead of internally added reactive reagents, features intrinsic baseline correction via on/off light switching and shows C-F bonds-type enhanced stability. It also affords selectivity imparted by the catalytic process and nano-level detection, such as 20 nM amoxicillin in μl sample volumes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000405466200002 |
Publication Date |
2017-07-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
26 |
Open Access |
|
Notes |
; Evonik is thanked for providing samples of silicon and titanium oxides. Support from the National Science Foundation (SMG) for a portion of this work is gratefully acknowledged. FWO and UAntwerpen (BOF) are acknowledged for financial support. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:144538 |
Serial |
5833 |
Permanent link to this record |
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|
|
Author |
De Henau, S.; Tilleman, L.; Vangheel, M.; Luyckx, E.; Trashin, S.; Pauwels, M.; Germani, F.; Vlaeminck, C.; Vanfleteren, J.R.; Bert, W.; Pesce, A.; Nardini, M.; Bolognesi, M.; De Wael, K.; Moens, L.; Dewilde, S.; Braeckman, B.P. |
Title |
A redox signalling globin is essential for reproduction in Caenorhabditis elegans |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
6 |
Issue |
|
Pages |
8782 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Moderate levels of reactive oxygen species (ROS) are now recognized as redox signalling molecules. However, thus far, only mitochondria and NADPH oxidases have been identified as cellular sources of ROS in signalling. Here we identify a globin (GLB-12) that produces superoxide, a type of ROS, which serves as an essential signal for reproduction in C. elegans. We find that GLB-12 has an important role in the regulation of multiple aspects in germline development, including germ cell apoptosis. We further describe how GLB-12 displays specific molecular, biochemical and structural properties that allow this globin to act as a superoxide generator. In addition, both an intra- and extracellular superoxide dismutase act as key partners of GLB-12 to create a transmembrane redox signal. Our results show that a globin can function as a driving factor in redox signalling, and how this signal is regulated at the subcellular level by multiple control layers. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000367577100002 |
Publication Date |
2015-12-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
20 |
Open Access |
|
Notes |
; We thank Dr K. Matsumoto and Dr T. Mizuno for kindly providing the mek-1(ks54) sek-1(km4) double mutant, the antibody anti-PMK-1 and technical advice on antibody use; Dr D. Kim for kindly providing the pDK177 RNAi strain; Dr M. Ubbink and Dr Q. Bashir for providing CCP; Dr K. Oegema and the OD lab for sharing technical expertise; M. Couvreur for assistance in generating transgenic lines; and Dr T. Dansen for the final support. Some strains were provided by the CGC, which is funded by the NIH Office of Research Infrastructure Programs (P40 OD010440). S.D.H. and F.G. are PhD fellows of the Fund for Scientific Research (FWO). Financial support to S.D. and L.M. was provided by the University of Antwerp (BOF UA TOP 2006), to K.D.W., S.D. and S.T. by the University of Antwerp (BOF-GOA) and to S.D., L.M., B.P.B., by FWO project G.0247.09. ; |
Approved |
Most recent IF: 12.124; 2015 IF: 11.470 |
Call Number |
UA @ admin @ c:irua:129310 |
Serial |
5809 |
Permanent link to this record |
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|
|
Author |
Meysman, F.J.R.; Cornelissen, R.; Trashin, S.; Bonne, R.; Hidalgo-Martinez, S.; van der Veen, J.; Blom, C.J.; Karman, C.; Hou, J.-L.; Eachambadi, R.T.; Geelhoed, J.S.; De Wael, K.; Beaumont, H.J.E.; Cleuren, B.; Valcke, R.; van der Zant, H.S.J.; Boschker, H.T.S.; Manca, J.V. |
Title |
A highly conductive fibre network enables centimetre-scale electron transport in multicellular cable bacteria |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
10 |
Pages |
4120 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Biological electron transport is classically thought to occur over nanometre distances, yet recent studies suggest that electrical currents can run along centimetre-long cable bacteria. The phenomenon remains elusive, however, as currents have not been directly measured, nor have the conductive structures been identified. Here we demonstrate that cable bacteria conduct electrons over centimetre distances via highly conductive fibres embedded in the cell envelope. Direct electrode measurements reveal nanoampere currents in intact filaments up to 10.1 mm long (>2000 adjacent cells). A network of parallel periplasmic fibres displays a high conductivity (up to 79 S cm(-1)), explaining currents measured through intact filaments. Conductance rapidly declines upon exposure to air, but remains stable under vacuum, demonstrating that charge transfer is electronic rather than ionic. Our finding of a biological structure that efficiently guides electrical currents over long distances greatly expands the paradigm of biological charge transport and could enable new bio-electronic applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
000485216900006 |
Publication Date |
2019-09-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
10 |
Open Access |
|
Notes |
; This research was financially supported by the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) through ERC Grant 306933 (F.J.R.M.), the Research Foundation Flanders (FWO project grant G031416N), and the Netherlands Organisation for Scientific Research (VICI grant 016.VICI.170.072 to F.J.R.M.). H.J.E.B., C.J.B. and H.S.J.Z. were supported by the Netherlands Organisation for Scientific Research (NWO/OCW), as part of the Frontiers of Nanoscience program. R.B. is supported by an 'aspirant' grant from Research Foundation Flanders (FWO). We thank Laurine Burdorf (UAntwerpen) for help with Thiothrix cultivation, Marlies Nijemeisland (Faculty of Aerospace, TU Delft) for assistance with Raman microscopy, and Jan D'Haen (UHasselt) and Renaat Dasseville (UGent) for help with EM imaging. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:162795 |
Serial |
5451 |
Permanent link to this record |
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|
|
Author |
Slavkovic, S.; Shoara, A.A.; Churcher, Z.R.; Daems, E.; De Wael, K.; Sobott, F.; Johnson, P.E. |
Title |
DNA binding by the antimalarial compound artemisinin |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Scientific reports |
Abbreviated Journal |
|
Volume |
12 |
Issue |
1 |
Pages |
133 |
Keywords |
A1 Journal article; Pharmacology. Therapy; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
Abstract |
Artemisinin (ART) is a vital medicinal compound that is used alone or as part of a combination therapy against malaria. ART is thought to function by attaching to heme covalently and alkylating a range of proteins. Using a combination of biophysical methods, we demonstrate that ART is bound by three-way junction and duplex containing DNA molecules. Binding of ART by DNA is first shown for the cocaine-binding DNA aptamer and extensively studied using this DNA molecule. Isothermal titration calorimetry methods show that the binding of ART is both entropically and enthalpically driven at physiological NaCl concentration. Native mass spectrometry methods confirm DNA binding and show that a non-covalent complex is formed. Nuclear magnetic resonance spectroscopy shows that ART binds at the three-way junction of the cocaine-binding aptamer, and that binding results in the folding of the structure-switching variant of this aptamer. This structure-switching ability was exploited using the photochrome aptamer switch assay to demonstrate that ART can be detected using this biosensing assay. This study is the first to demonstrate the DNA binding ability of ART and should lay the foundation for further work to study implications of DNA binding for the antimalarial activity of ART. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000740510500120 |
Publication Date |
2022-01-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:184507 |
Serial |
8851 |
Permanent link to this record |
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|
|
Author |
De Jong, M.; Sleegers, N.; Kim, J.; Van Durme, F.; Samyn, N.; Wang, J.; De Wael, K. |
Title |
Electrochemical fingerprint of street samples for fast on-site screening of cocaine in seized drug powders |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Chemical science |
Abbreviated Journal |
Chem Sci |
Volume |
|
Issue |
|
Pages |
1-7 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
We report on a wearable fingertip sensor for on-the-spot identification of cocaine and its cutting agents in street samples. Traditionally, on-site screening is performed by means of colour tests which are difficult to interpret and lack selectivity. By presenting the distinct voltammetric response of cocaine, cutting agents, binary mixtures of cocaine and street samples in solution and powder street samples, we were able to elucidate the electrochemical fingerprint of all these compounds. The new electrochemical concept holds considerable promise as an on-site screening method. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000371021900094 |
Publication Date |
2016-01-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-6520 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.668 |
Times cited |
37 |
Open Access |
|
Notes |
; The authors acknowledge BELSPO for funding the APTADRU project (BR/314/PI/ APTADRU). ; |
Approved |
Most recent IF: 8.668 |
Call Number |
UA @ admin @ c:irua:130404 |
Serial |
5591 |
Permanent link to this record |