Electrochemical detection of the synthetic cathinone 3,4-methylenedioxypyrovalerone using carbon screen-printed electrodes: A fast, simple and sensitive screening method for forensic samples

Abstract

In this work, the electrochemical detection of 3,4-methylenedioxypyrovalerone (MDPV), a synthetic cathinone used as a stimulant drug, is presented for the first time. The electrochemical behavior of MDPV was studied by cyclic voltammetry (CV) at the surface of an unmodified glassy carbon electrode and a carbon graphite screen-printed electrode (SPE-Gr), where three irreversible oxidation processes were identified. The quantification of MDPV in seized drug samples was optimized for the first oxidation process (at + 0.6 V vs Ag) in 0.1 mol L−1 Britton Robison (BR) buffer solution pH 6.0 at SPE-Gr, using adsorptive stripping differential pulse voltammetry (AdSDPV) detection. The proposed method exhibited a limit of detection (LOD) of 0.5 µmol L−1 and suitable electrochemical response stability using the same (N = 5) or different (N = 3) electrodes, both presenting a RSD lower than 1.6%. Additionally, interference studies and application to MDPV sensing in reference samples provided by United Nations Office on Drugs and Crime (UNODC) were performed, confirming the potential of the proposed sensor for application in forensic analysis as a simple, fast and cost-effective screening method for MDPV.