Preparation, characterization, and evaluation of an acetylene black polyurethane composite electrode modified with copper nanoparticles for the determination of escitalopram

Abstract

Escitalopram (ESC) is a widely prescribed antidepressive drug worldwide and must be monitored in biological fluids and environmental samples. Thus the preparation of an acetylene black-polyurethane composite electrode modified with copper metallic nanoparticles by electrodeposition intended for the determination of ESC in synthetic urine and mineral water samples is presented. The surface was further electrochemically pretreated in 0.50 mol L−1 NaOH in order to obtain a stable mixture of Cu (II) oxides on top of the Cu° nanoparticles. After preconditioning in 0.10 mol L−1 phosphate buffer pH = 7.0, the modified electrode was used in the determination of ESC in the proposed matrixes using CV and DPV, after optimizing experimental parameters. The interaction of the analyte with copper (II) ions promoted a decrease of the Cu(II) reduction peak which was proportional to the ESC concentration in the 0.020–0.10 µmol L−1 (LOD = (5 ± 1) nmol L−1) and 0.040–0.20 µmol L−1 (LOD = (5.1 ± 0.9) nmol L−1) in cyclic voltammetry (CV) and differential pulse voltammetry (DPV) respectively. Interferences from ascorbic acid, uric acid, dopamine and creatinine were evaluated, however the last one present in synthetic urine did not prevented the determination of ESC, as well as the other chemical species naturally present in the mineral water.