An electrochemical sensor for selective determination of sulfamethoxazole in surface water using a molecularly imprinted polymer modified BDD electrode

This study presents a new electrochemical sensor based on a molecularly imprinted polymer (MIP) modified boron doped diamond (BDD) electrode (MIP/BDD electrode) for the quantitative determination of sulfamethoxazole (SMX). This MIP/BDD electrode is prepared by in situ electro-polymerization of pyrrole (Py) on the BDD electrode in the presence of SMX. This sensor based on the MIP/BDD electrode performs a linear response for SMX from 0.1-100 mu M with a limit of detection of 24.1 nM (S/N = 3) and a highly reproducible response (2.32%). The detection of SMX in surface water samples spiked at different concentration levels performs satisfactorily at a recovery of 96.0-106.2%. Furthermore, this sensor exhibits a superior selectivity to recognize SMX molecules even compared with other structural analogues (SDM, SD and SIZ). This high-selectivity determination originates from the imprinted sites of the MIP film which have the advantages of appropriate cavity size and homologous functional groups for the specific recognition of SMX molecules. This specially designed sensor offers a simple, selective, sensitive, reliable, stable and environmentally friendly approach for SMX determination, providing a responsible strategy for effective SMX analysis in environmental water.