A highly accurate portable electrochemical sensor for cocaine

Subtitle:from methodology to testing in the field

Illicit drugs are everywhere in our society. The clandestine market is growing faster than ever before, with record breaking seizures in Europe (and particularly Belgium) concerning cocaine. Cocaine is singled out as a major substance of interest, in Europe and Belgium in particular. Currently used field tests for cocaine detection have several downfalls. They lack specificity, leading to false positive results, and are also easily bypassed by adding other (often colored) compounds, producing many false negative results. This lack of accuracy causes large costs for society: juridical, health-wise and economical. This, combined with the continuously growing drug retail market, presses the need for new and better portable detection devices for cocaine. This PhD thesis aimed at the development of a portable, reliable electrochemical sensor device for cocaine, allowing accurate analysis in field settings such as the Port of Antwerp. The potential of the electrochemical approach to replace other field techniques was tested and evaluated throughout the project. Electrochemical detection, square-wave voltammetry in particular, allows a fast (<40 s) analysis with high sensitivity, specificity and the possibility to detect multiple compounds (illicit drugs, adulterants and diluents) in one measurement scan, making it perfect for on-site screening purposes. In order to obtain this optimized electrochemical approach for cocaine, several fundamental and applied research steps were conducted of which the results are presented in this thesis: (1) determination of methodology and identification of interfering compounds, (2) defining the interfering mechanism of these compounds and provide solutions, (3) test possibility towards polydrug analysis (heroin), and (4) validation and field testing. This approach was followed to guide our fundamental research towards a highly relevant application. This PhD involved close collaboration with the National Institute for Criminalistics and Criminology, as well as with the Netherlands Forensic Institute, the Federal Judicial Police and Belgian Customs. All these agencies provided expert insights into the topic, as well as access to confiscated cocaine street and smuggle samples to help validating the developed technology. Lab validation on 374 samples delivered an accuracy of 98.4 % for the developed sensor, while the field measurements presented clear advantages over other screening tests, certainly concerning the detection of cocaine in colored and mixed smuggle samples. In conclusion, this work includes the research foundations to bring this cocaine detection technology to the market, where it has the potential to replace other commonly used screening techniques.

Publication year:2020

Keywords:Doctoral thesis

Accessibility:Closed