Development of screen printed chemically modified electrodes for the voltammetric determination of cocaine and LSD in samples of forensic interest

Abstract

This project aims the research and development of transducers for the voltammetric determination of cocaine and LSD in samples of narcotics seized by the police. Considering the fact that all these species show electrochemical response by chemical oxidation or reduction in conventional electrode surface, this project proposes the chemical modification of electrode surface by thin films, using dip coating or spin coating processes. As surface modifiers, fourteen Schiff bases will be used (Salen and Salcn structures) with different cations anchored at them (Co, Fe, Cu, Ni, V and U), and will be investigated also three species of cucurbiturils. Improved selectivity and chemical specificity are expected with these surface modifications, as well as an increase in the amperometric sensitivity for these analytes. In the subsequent step, the chemical films that present the best results in terms of selectivity and specificity should be used in two different fronts, namely: 1) application of the screen printed chemically modified electrodes in field (detection of these illicit drugs in drug traffic scene); 2) study of the viability of these portable transductors for actuating as solid-phase extraction of the described analytes, with subsequent analysis of their surfaces by a gas chromatograph coupled to a mass spectrometer (GC-MS) with a direct ionization system in real time. (AU)