Electrochemical determination of sulfamethoxazole in biological and drug samples using Ce (III)-doped CuO modified electrode

Abstract

This study aimed to fabricate Ce (III)-doped CuO via a simple participation technique. The produced nanocomposite as an effective modifier was applied at the surface of screen-printed electrode (SPE) to evaluate the electro-oxidation of sulfamethoxazole (SMX). Using K3Fe(CN)6 and related equation, electro-active area of electrodes was calculated that were 0.041, 0.111 and 0.123 cm2 for SPE, CuO/SPE and Ce (III)-doped CuO/SPE, respectively. The results of scan rate investigation revealed the diffusion-controlled mechanism of SMX on Ce (III)-doped CuO/SPE. The developed electrode displayed good electrocatalytic activity toward oxidation of SMX and had a broad linear range of 0.03–360 µM, a low limit of detection (LOD) of 0.01 µM, acceptable reproducibility and excellent selectivity under optimized conditions. Moreover, diffusion coefficient was calculated 1.44 × 10−5 cm2 s−1 using chronoamperometry technique. The successful applicability of the sensor was confirmed to detect SMX in real samples, with suitable recoveries.