Eco‐Friendly Voltammetric Quantification of Paroxetine Using a Graphene–Copper Oxide Nanohybrid‐Based Electrode

Abstract

This study reports the design, fabrication, and characterization of a novel carbon paste electrode integrated with graphene and copper oxide nanohybrid (Gr/CuONPs/CPE) for the sensitive and selective voltammetric determination of the serotonin reuptake inhibitor paroxetine (PAR). Modification of the electrode surface with Gr/CuONPs nanohybrid facilitated a more efficient electrochemical oxidation of PAR at 1.046 V in BR buffer (pH 6) based on the synergistic electrocatalytic effect of the nanohybrid components and the enhanced electroactive surface area provided by the nanostructure. The electroanalytical investigations combined with molecular orbital calculations revealed a diffusion‐controlled mechanism through oxidation of the pyrimidine nitrogen atom (N6), accompanied with the transfer of two protons/one electron. At the optimized Gr/CuONPs ratio within the nanohybrid, the cited electrode demonstrated a linear response within the PAR concentrations ranged from 0.066 to 4.939 µg mL −1 and an limit of detection value of 45.4 ng mL −1 . The Gr/CuONPs/CPE exhibited extended storage stability with excellent fabrication and electrochemical measurement reproducibility. Based on the environmental impact of PAR, the developed voltammetric procedure was effectively applied for monitoring of PAR residues in surface water samples and marketed formulations with acceptable recoveries. The green analytical metrics (Analytical Eco‐Scale and Analytical GrEEness metric approach) were evaluated, highlighting the method's environmental friendliness of the suggested voltammetric procedures.