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Author Schram, J. file  openurl
  Title Electrochemical sensing strategies for multiple illicit drugs Type Doctoral thesis
  Year (down) 2024 Publication Abbreviated Journal  
  Volume Issue Pages 290 p.  
  Keywords Doctoral thesis; Pharmacology. Therapy; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)  
  Abstract Today, illicit drugs are omnipresent in society. Clandestine markets are growing faster than ever before, record amounts of cocaine are seized in seaports and airports, while the associated violence is spiralling out of control. In addition, drug monitoring centres worldwide are warning for the increasing complexity of the drug markets, as the traditionally popular drugs are joined by countless new synthetic variants, while medical drugs are also increasingly being abused. In order to provide services confronted with illicit drug samples (police, customs, forensic scientists, first responders, …) with important information on the identity of an unknown sample, suitable analytical tests are required. While these exist for laboratory environments, on-site applicable tests are important to accelerate the decision-making process. Electrochemical sensors have all the advantages required for such on-site tests: they are fast, portable, easy-to-use and reliable. Furthermore, they are not influenced by colours, which are frequently added to drug samples to deceive the existing tests. Previous work has mainly focussed on the detection of a single drug per analysis. However, many drugs could be encountered due to the diversity of the drug markets. Therefore, this project developed electrochemical strategies for the detection of multiple drugs simultaneously. First, the electrochemical behaviour of the individual drugs was studied in different measuring conditions (assessing the influence of pH, concentration and temperature). Then, all findings and strategies were combined to detect multiple targets simultaneously. An electrochemical sensor was developed for the four most popular drugs at music festivals: cocaine, MDMA, amphetamine and ketamine. This sensor generates a so-called ‘superfingerprint’ of the sample, which is then automatically interpreted by a developed algorithm in order to produce a straightforward output. Finally, a pill analysis sensor was developed in the context of drug checking services, where a consumer can anonymously have a sample chemically analysed to obtain information on the composition, dose and potentially harmful additives. The sensor achieved an outstanding accuracy in identifying the main component and provided the option to quantify, as well as an indication on the presence of other substances in the sample. The project’s findings demonstrate the potential for electrochemistry in illicit drug detection and provide a basis for the development of new sensors, targeting other drug combinations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:203199 Serial 9029  
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Author Van Echelpoel, R.; Schram, J.; Parrilla, M.; Daems, D.; Slosse, A.; Van Durme, F.; De Wael, K. url  doi
openurl 
  Title Electrochemical methods for on-site multidrug detection at festivals Type A1 Journal article
  Year (down) 2022 Publication Sensors & Diagnostics Abbreviated Journal  
  Volume 1 Issue 1 Pages 793-802  
  Keywords A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)  
  Abstract Two electrochemical methodologies, i.e. flowchart and dual-sensor, were developed to aid law enforcement present at festivals to obtain a rapid indication of the presence of four illicit drugs in suspicious samples encountered.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2022-06-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:188521 Serial 8856  
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Author Schram, J.; Parrilla, M.; Slosse, A.; Van Durme, F.; Åberg, J.; Björk, K.; Bijvoets, S.M.; Sap, S.; Heerschop, M.W.J.; De Wael, K. pdf  url
doi  openurl
  Title Paraformaldehyde-coated electrochemical sensor for improved on-site detection of amphetamine in street samples Type A1 Journal article
  Year (down) 2022 Publication Microchemical journal Abbreviated Journal  
  Volume 179 Issue Pages 107518-107519  
  Keywords A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)  
  Abstract The increasing illicit production, distribution and abuse of amphetamine (AMP) poses a challenge for law enforcement worldwide. To effectively combat this issue, fast and portable tools for the on-site screening of suspicious samples are required. Electrochemical profile (EP)-based sensing of illicit drugs has proven to be a viable option for this purpose as it allows rapid voltammetric measurements via the use of disposable and low-cost graphite screen-printed electrodes (SPEs). In this work, a highly practical paraformaldehyde (PFA)-coated sensor, which unlocks the detectability of primary amines through derivatization, is developed for the on-site detection of AMP in seized drug samples. A potential interval was defined at the sole AMP peak (which is used for identification of the target analyte) to account for potential shifts due to fluctuations in concentration and temperature, which are relevant factors for on-site use. Importantly, it was found that AMP detection was not hindered by the presence of common diluents and adulterants such as caffeine, even when present in high amounts. When inter-drug differentiation is desired, a simultaneous second test with the same solution on an unmodified electrode is introduced to provide the required additional electrochemical information. Finally, the concept was validated by analyzing 30 seized AMP samples (reaching a sensitivity of 96.7 %) and comparing its performance to that of commercially available Raman and Fourier Transform Infrared (FTIR) devices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000809675500010 Publication Date 2022-04-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0026-265x; 0026-265x 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:188454 Serial 8910  
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Author Dragan, A.-M.; Truta, F.M.; Tertis, M.; Florea, A.; Schram, J.; Cernat, A.; Feier, B.; De Wael, K.; Cristea, C.; Oprean, R. url  doi
openurl 
  Title Electrochemical fingerprints of illicit drugs on graphene and multi-walled carbon nanotubes Type A1 Journal article
  Year (down) 2021 Publication Frontiers In Chemistry Abbreviated Journal Front Chem  
  Volume 9 Issue Pages 641147  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Illicit drugs use and abuse remains an increasing challenge for worldwide authorities and, therefore, it is important to have accurate methods to detect them in seized samples, biological fluids and wastewaters. They are recently classified as the latest group of emerging pollutants as their consumption increased tremendously in recent years. Nanomaterials have gained much attention over the last decade in the development of sensors for a myriad of applications. The applicability of these nanomaterials, functionalized or not, significantly increases and it is therefore highly suitable for use in the detection of illicit drugs. We have assessed the suitability of various nanoplatforms, such as graphene (GPH), multi-walled carbon nanotubes (MWCNTs), gold nanoparticles (AuNPs) and platinum nanoparticles (PtNPs) for the electrochemical detection of illicit drugs. GPH and MWCNTs were chosen as the most suitable platforms and cocaine, 3,4-methylendioxymethamfetamine (MDMA), 3-methylmethcathinone (MMC) and alpha-pyrrolidinovalerophenone (PVP) were tested. Due to the hydrophobicity of the nanomaterials-based platforms which led to low signals, two strategies were followed namely, pretreatment of the electrodes in sulfuric acid by cyclic voltammetry and addition of Tween 20 to the detection buffer. Both strategies led to an increase in the oxidation signal of illicit drugs. Binary mixtures of illicit drugs with common adulterants found in street samples were also investigated. The proposed strategies allowed the sensitive detection of illicit drugs in the presence of most adulterants. The suitability of the proposed sensors for the detection of illicit drugs in spiked wastewaters was finally assessed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000634708900001 Publication Date 2021-03-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2296-2646 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.994 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 3.994  
  Call Number UA @ admin @ c:irua:177704 Serial 7861  
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Author Schram, J.; Parrilla, M.; Sleegers, N.; Van Durme, F.; van den Berg, J.; van Nuijs, A.L.N.; De Wael, K. pdf  url
doi  openurl
  Title Electrochemical profiling and liquid chromatography–mass spectrometry characterization of synthetic cathinones : from methodology to detection in forensic samples Type A1 Journal article
  Year (down) 2021 Publication Drug Testing And Analysis Abbreviated Journal Drug Test Anal  
  Volume 13 Issue 7 Pages 1282-1294  
  Keywords A1 Journal article; Pharmacology. Therapy; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre  
  Abstract The emergence of new psychoactive drugs in the market demands rapid and accurate tools for the on‐site classification of illegal and legal compounds with similar structures. Herein, a novel method for the classification of synthetic cathinones (SC) is presented based on their electrochemical profile. First, the electrochemical profile of five common SC (i.e., mephedrone, ethcathinone, methylone, butylone and 4‐chloro‐alpha‐pyrrolidinovalerophenone) is collected to build calibration curves using square wave voltammetry on graphite screen‐printed electrodes (SPE). Second, the elucidation of the oxidation pathways, obtained by liquid chromatography‐high resolution mass spectrometry, allows the pairing of the oxidation products to the SC electrochemical profile, providing a selective and robust classification. Additionally, the effect of common adulterants and illicit drugs on the electrochemical profile of the SC is explored. Interestingly, a cathodic pretreatment of the SPE allows the selective detection of each SC in presence of electroactive adulterants. Finally, the electrochemical approach is validated with gas‐chromatography‐mass spectrometry by analyzing 26 confiscated samples from seizures and illegal webshops. Overall, the electrochemical method exhibits a successful classification of SC including structural derivatives, a crucial attribute in an ever‐diversifying drug market.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000624902500001 Publication Date 2021-02-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1942-7603; 1942-7611 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.469 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 3.469  
  Call Number UA @ admin @ c:irua:175583 Serial 7863  
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Author Schram, J.; Thiruvottriyur Shanmugam, S.; Sleegers, N.; Florea, A.; Samyn, N.; van Nuijs, A.L.N.; De Wael, K. pdf  doi
openurl 
  Title Local conversion of redox inactive molecules into redox active ones : a formaldehyde based strategy for the electrochemical detection of illicit drugs containing primary and secondary amines Type A1 Journal article
  Year (down) 2021 Publication Electrochimica Acta Abbreviated Journal Electrochim Acta  
  Volume 367 Issue Pages 137515  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre  
  Abstract Electrochemical techniques have evidenced to be highly suitable for the development of portable, rapid and accurate screening methods for the detection of illicit drugs in seized samples. However, the redox inactivity of primary amines, one of the most common functional groups of illicit drugs, masks voltammetric detection in aqueous environment at carbon electrodes and, therefore, leads to false negative results if only these primary amines are present in the structures. This work explores the feasibility of a derivatisation approach that introduces formaldehyde in the measuring conditions in order to achieve methylation, via an Eschweiler-Clarke mechanism, of illicit drugs containing primary and secondary amines, using amphetamine (AMP) and methamphetamine (MET) as model molecules. As a result the electrochemical fingerprint is enriched and thereby the detectability enhanced. A combination of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOFMS) and square-wave voltammetric (SWV) measurements is employed to identify reaction products and link them to the observed redox peaks. Although an alkaline environment (pH 12.0) proved to increase the reaction yield, a richer electrochemical fingerprint (EF) is obtained in neutral conditions (pH 7.0). Similarly, the addition of formate improved the reaction conversion but reduced the EF by eliminating a redox peak that is attributed to side products formed in the absence of formate. To illustrate the applicability, the derivatisation strategy is applied to several prominent illicit drugs containing primary and secondary amines to demonstrate its EF enriching capabilities. Finally, real street samples from forensic seizures are analysed. Overall, this strategy unlocks the detectability of the hitherto undetectable AMP and other drugs only containing primary amines, while strongly facilitating the identification of MET and analogues. These findings are not limited to illicit drugs, the insights can ultimately be applied to other target molecules containing similar functional groups. (C) 2020 Published by Elsevier Ltd.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000607620700010 Publication Date 2020-11-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0013-4686 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.798 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 4.798  
  Call Number UA @ admin @ c:irua:176083 Serial 8177  
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Author de Jong, M.; Sleegers, N.; Schram, J.; Daems, D.; Florea, A.; De Wael, K. pdf  url
doi  openurl
  Title A Benzocaine‐Induced Local Near‐Surface pH Effect: Influence on the Accuracy of Voltammetric Cocaine Detection Type A1 Journal article
  Year (down) 2020 Publication Analysis & Sensing Abbreviated Journal Anal. Sens.  
  Volume Issue Pages anse.202000012  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract This work reports on a local induced near-surface pH effect (pHS), due to the presence of one analyte, leading to an influence or even suppression of redox signals of a second analyte present in solution. This concept and its impact on voltammetric sensing is illustrated by focusing on the detection of cocaine in the presence of the common adulterant benzocaine. An in-depth study on the occurring interference mechanism and why it occurs for benzocaine specifically and not for other adulterants was performed through the use of multiple electrochemical strategies. It was concluded that the potential shift and loss of intensity of the squarewave voltammetric cocaine signal in the presence of benzocaine was caused by a local pHS effect. A cathodic pretreatment strategy was developed to nonetheless allow accurate cocaine detection. The gathered insights are useful to explain unidentified phenomena involving compounds with properties similar to benzocaine in voltammetric electroanalysis.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2020-10-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2629-2742 ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes The authors acknowledge financial support from IOF-SBO/POC (UAntwerp), the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N and Grant 1SB 8120N, and VLAIO IM [HBC.2019.2181]. Approved Most recent IF: NA  
  Call Number AXES @ axes @c:irua:173031 Serial 6427  
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Author Schram, J.; Parrilla, M.; Sleegers, N.; Samyn, N.; Bijvoets, S.M.; Heerschop, M.W.J.; van Nuijs, A.L.N.; De Wael, K. pdf  doi
openurl 
  Title Identifying Electrochemical Fingerprints of Ketamine with Voltammetry and Liquid Chromatography–Mass Spectrometry for Its Detection in Seized Samples Type A1 Journal article
  Year (down) 2020 Publication Analytical Chemistry Abbreviated Journal Anal Chem  
  Volume 92 Issue 19 Pages 13485-13492  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre  
  Abstract Herein, a straightforward electrochemical approach for the determination of ketamine in street samples and seizures is presented by employing screen-printed electrodes (SPE). Square wave voltammetry (SWV) is used to study the electrochemical behavior of the illicit drug, thus profiling the different oxidation states of the substance at different pHs. Besides, the oxidation pathway of ketamine on SPE is investigated for the first time with liquid chromatography–high-resolution mass spectrometry. Under the optimized conditions, the calibration curve of ketamine at buffer solution (pH 12) exhibits a sensitivity of 8.2 μA μM–1, a linear relationship between 50 and 2500 μM with excellent reproducibility (RSD = 2.2%, at 500 μM, n = 7), and a limit of detection (LOD) of 11.7 μM. Subsequently, binary mixtures of ketamine with adulterants and illicit drugs are analyzed with SWV to investigate the electrochemical fingerprint. Moreover, the profile overlapping between different substances is addressed by the introduction of an electrode pretreatment and the integration of a tailor-made script for data treatment. Finally, the approach is tested on street samples from forensic seizures. Overall, this system allows for the on-site identification of ketamine by law enforcement agents in an easy-to-use and rapid manner on cargos and seizures, thereby disrupting the distribution channel and avoiding the illicit drug reaching the end-user.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000580426800091 Publication Date 2020-10-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.4 Times cited Open Access  
  Notes Universiteit Antwerpen; H2020 Societal Challenges, 833787 ; Fonds Wetenschappelijk Onderzoek, 1S3765817N 1SB8120N ; Approved Most recent IF: 7.4; 2020 IF: 6.32  
  Call Number AXES @ axes @c:irua:170523 Serial 6435  
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Author Florea, A.; Schram, J.; De Jong, M.; Eliaerts, J.; Van Durme, F.; Kaur, B.; Samyn, N.; De Wael, K. url  doi
openurl 
  Title Electrochemical strategies for adulterated heroin samples Type A1 Journal article
  Year (down) 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  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000472682000056 Publication Date 2019-05-30  
  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 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  
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