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	Author	Eliaerts, J.; Meert, N.; Dardenne, P.; Van Durme, F.; Baeten, V.; Samyn, N.; De Wael, K.
	Title	Evaluation of a calibration transfer between a bench top and portable Mid-InfraRed spectrometer for cocaine classification and quantification			Type	A1 Journal article
	Year	2020	Publication	Talanta	Abbreviated Journal	Talanta
	Volume	209	Issue		Pages	120481
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	A portable Fourier Transform Mid-InfraRed (FT-MIR) spectrometer using Attenuated Total Reflectance (ATR) sampling is used for daily routine screening of seized powders. Earlier, ATR-FT-MIR combined with Support Vector Machines (SVM) algorithms resulted in a significant improvement of the screening method to a reliable and straightforward classification and quantification tool for both cocaine and levamisole. However, can this tool be transferred to new (hand-held) devices, without loss of the extensive data set? The objective of this study was to perform a calibration transfer between a newly purchased bench top (BT) spectrometer and a portable (P) spectrometer with existing calibration models. Both instruments are from the same brand and have identical characteristics and acquisition parameters (FT instrument, resolution of 4 cm(-1) and wavenumber range 4000 to 500 cm(-1)). The original SVM classification model (n = 515) and SVM quantification model (n = 378) were considered for the transfer trial. Three calibration transfer strategies were assessed: 1) adjustment of slope and bias; 2) correction of spectra from the new instrument BT to P using Piecewise Direct Standardization (PDS) and 3) building a new mixed instrument model with spectra of both instruments. For each approach, additional cocaine powders were measured (n = 682) and the results were compared with GC-MS and GC-FID. The development of a mixed instrument model was the most successful in terms of performance. The future strategy of a mixed model allows applying the models, developed in the laboratory, to portable instruments that are used on-site, and vice versa. The approach offers opportunities to exchange data within a network of forensic laboratories using other FT-MIR spectrometers.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000509632900016	Publication Date	2019-10-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0039-9140; 1873-3573	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.1	Times cited	2	Open Access
	Notes	; ;			Approved	Most recent IF: 6.1; 2020 IF: 4.162
	Call Number	UA @ admin @ c:irua:166475			Serial	6511
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	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
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000656959000033	Publication Date	2021-01-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		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
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	Author	Daems, E.; Dewaele, D.; Barylyuk, K.; De Wael, K.; Sobott, F.
	Title	Aptamer-ligand recognition studied by native ion mobility-mass spectrometry			Type	A1 Journal article
	Year	2021	Publication	Talanta	Abbreviated Journal	Talanta
	Volume	224	Issue		Pages	121917
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	The range of applications for aptamers, small oligonucleotide-based receptors binding to their targets with high specificity and affinity, has been steadily expanding. Our understanding of the mechanisms governing aptamer-ligand recognition and binding is however lagging, stymieing the progress in the rational design of new aptamers and optimization of the known ones. Here we demonstrate the capabilities and limitations of native ion mobility-mass spectrometry for the analysis of their higher-order structure and non-covalent interactions. A set of related cocaine-binding aptamers, displaying a range of folding properties and ligand binding affinities, was used as a case study in both positive and negative electrospray ionization modes. Using carefully controlled experimental conditions, we probed their conformational behavior and interactions with the high-affinity ligand quinine as a surrogate for cocaine. The ratios of bound and unbound aptamers in the mass spectra were used to rank them according to their apparent quinine-binding affinity, qualitatively matching the published ranking order. The arrival time differences between the free aptamer and aptamer-quinine complexes were consistent with a small ligand-induced conformational change, and found to inversely correlate with the affinity of binding. This mass spectrometry-based approach provides a fast and convenient way to study the molecular basis of aptamer-ligand recognition.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000600787800122	Publication Date	2020-12-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0039-9140; 1873-3573	ISBN		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:174086			Serial	7490
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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.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000668000500108	Publication Date	2021-06-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0039-9140; 1873-3573	ISBN		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
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	Author	Janssens, K.; van der Snickt, G.; Vanmeert, F.; Legrand, S.; Nuyts, G.; Alfeld, M.; Monico, L.; Anaf, W.; de Nolf, W.; Vermeulen, M.; Verbeeck, J.; De Wael, K.
	Title	Non-invasive and non-destructive examination of artistic pigments, paints, and paintings by means of X-Ray methods			Type	A1 Journal article
	Year	2016	Publication	Topics in Current Chemistry	Abbreviated Journal	Topics Curr Chem
	Volume	374	Issue	374	Pages	81
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Microscopic XRF is a variant of the method that is well suited to visualize the elemental distribution of key elements, mostly metals, present in paint multi-layers, on the length scale from 1 to 100 μm inside micro-samples taken from paintings. In the context of the characterization of artists pigments subjected to natural degradation, the use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS and μ-XRD have proven themselves to be very suitable for such studies. Their use is often combined with microscopic Fourier transform infra-red spectroscopy and/or Raman microscopy since these methods deliver complementary information of high molecular specificity at more or less the same length scale as the X-ray microprobe techniques. Since microscopic investigation of a relatively limited number of minute paint samples, taken from a given work of art, may not yield representative information about the entire artefact, several methods for macroscopic, non-invasive imaging have recently been developed. Those based on XRF scanning and full-field hyperspectral imaging appear very promising; some recent published results are discussed.
	Address
	Corporate Author				Thesis
	Publisher	Springer international publishing ag	Place of Publication	Cham	Editor
	Language		Wos	000391178900006	Publication Date	2016-11-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2365-0869;2364-8961;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.033	Times cited	50	Open Access
	Notes	; ;			Approved	Most recent IF: 4.033
	Call Number	UA @ lucian @ c:irua:139930UA @ admin @ c:irua:139930			Serial	4443
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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
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000723747000009	Publication Date	2021-09-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		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:183268			Serial	7460
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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
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000682179000010	Publication Date	2021-04-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		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
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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
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000508389000028	Publication Date	2019-12-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		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
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