Electroanalytical profiling of cocaine samples by means of an electropolymerized molecularly imprinted polymer using benzocaine as the template molecule
The analysis of 'cutting' or additive agents in cocaine, like benzocaine (BZC), allows police analysts to identify each component of the sample, thus obtaining information like the drugs' provenience. This kind of drug profiling is of great value in tackling drug trafficking. Electrop...
Saved in:
Published in | Analyst (London) Vol. 146; no. 5; pp. 1747 - 1759 |
---|---|
Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Royal Society of Chemistry
07.03.2021
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The analysis of 'cutting' or additive agents in cocaine, like benzocaine (BZC), allows police analysts to identify each component of the sample, thus obtaining information like the drugs' provenience. This kind of drug profiling is of great value in tackling drug trafficking. Electropolymerized molecularly imprinted polymers (e-MIPs) on portable screen-printed carbon electrodes (SPCEs) were developed in this study for BZC determination. The MIPs' electropolymerization was performed on a carbon surface using the anaesthetic BZC as the template molecule and 3-amino-4-hydroxybenzoic acid (3,4-AHBA) as the functional monomer. The build-up of this biomimetic sensor was carefully characterized by cyclic voltammetry (CV) and optimized. Cyclic voltammetric investigation demonstrated that BZC oxidation had a complex and pH-dependent mechanism, but at pH 7.4 a single, well-defined oxidation feature was observed. The BZC-MIP interactions were studied by computer-aided theoretical modeling by means of density functional theory (DFT) calculations. The electroanalytical methodology was effectively applied to artificial urine samples; BZC molecular recognition was achieved with a low limit of detection (LOD) of 2.9 nmol L
−1
employing square-wave voltammetry (SWV). The e-MIPs were then used to 'fingerprint' genuine cocaine samples, assisted by principal component analysis (PCA), at the central forensic laboratory of the Brazilian Federal Police (BFP) with a portable potentiostat. This electroanalysis provided proof-of-concept that the drugs could be voltammetrically 'fingerprinted' using e-MIPs supported by chemometric analysis.
Cocaine samples were 'finger-printed' using e-MIPs, constructed on the surface of portable SPCEs. The SWV data with suitable chemometric analysis provides valuable information about the drugs' provenience which is crucial to tackle drug traffic. |
---|---|
Bibliography: | 10.1039/d0an02274h Electronic supplementary information (ESI) available. See DOI |
ISSN: | 0003-2654 1364-5528 |
DOI: | 10.1039/d0an02274h |