[N(CH3)4]2CoCl2Br2 based photoelectrochemical sensor for sulfamethoxazole detection in aqueous environments

A photoelectrochemical sensor for sulfamethoxazole (SMX) detection was prepared by a simple spin coating based on [N(CH3)4]2CoCl2Br2. The prepared membrane was broadly characterized using different analytical techniques to examine its morphological, wettability, electrochemical, and optical properties. In addition, the interaction mechanism between [N(CH3)4]2CoCl2Br2 and the antibiotic was determinated using absorbance and fluorescence measurements. The impedimetric sensor has exhibited good response towards SMX presenting remarkable limit of detection (LOD) of 2.5 × 10–12 M and limit of quantification (LOQ) of 8.3 × 10–12 M in darkness. Under illumination, LOD and LOQ values have decreased to be 6.3 × 10–13 M and 2.1 × 10–12 M, respectively. The recognition capability has correlated linearly with the SMX concentration in the range of 10–11–10–5 M under the two conditions. Finally, the sensitive thin film has presented high selectivity towards the cibled antibiotic, as well as good regeneration, repeatability and reproducibility.