Highly sensitive and selective electrochemical sensor for the determination of chloramphenicol

Recently, there has been significant interest in the utilization of indium-doped cadmium sulfide (CdS) for the detection of chloramphenicol (CAP) in food samples due to its exceptional performance. The objective of this research is to develop a simple, rapid, and highly sensitive sensor for CAP detection. CdS possesses remarkable characteristics as a semiconductor material, including a large specific surface area, abundant pore structure, and excellent electrical conductivity. The electrochemical properties of glassy carbon electrodes (GCE) were comprehensively investigated both in their pristine state and when modified with CdS/GCE, CdIn2S4/GCE, Cd1.5In2S4.5/GCE, and Cd2In2S5/GCE. The surface areas of the modified electrodes CdIn2S4/GCE, Cd1.5In2S4.5/GCE, and Cd2In2S5/GCE were measured to be 0.08 cm2, 0.097 cm2, and 0.25 cm2, respectively. Five replicate samples using the optimized proportioned electrode Cd2In2S5/GCE resulted in a response error below 5%. These results indicate that the composite demonstrates exceptional conductivity and reproducibility while maintaining satisfactory sensitivity and high specificity. The proposed sensor based on Cd2In2S5/GCE exhibited an impressive dynamic linear range from 10 nmol/L to 20 μmol/L with an exceptionally low detection limit of 3.8 nmol/L and remarkable sensitivity of 0.38 μA μm−1 cm−2. This sensor successfully quantified CAP in water samples with a satisfactory recovery rate ranging from 99.5% to 100.3%, accompanied by an RSD below 7.6%. Consequently,this developed electrochemical sensor presents itself as the optimal choice for simultaneous determination of CAP in both food and water samples.