An oxygen-deficient tin oxide-modified electrode for nanomolar detection of chloramphenicol†

Chloramphenicol (CPL) is a broad-spectrum antibiotic belonging to the class of antimicrobials. The European Union and other countries have restricted the use of CPL in animal husbandry due to concerns about antibiotic resistance. Hence, monitoring CPL in animal food and environmental water samples is highly essential. In this context, we developed a low-cost sensing matrix of oxygen-deficient tin oxide (DSnO₂) nanoparticles to determine CPL. The existence of oxygen deficiency was confirmed using various physicochemical characterization techniques. Electrochemical studies were performed by different voltammetry techniques, such as CV, LSV, and DPV, for CPL detection using DSnO₂/GCE. The voltammetry results deduce that under optimal conditions, DSnO₂ can readily interact with the nitro group of the CPL molecule, which increases the sensitivity towards CPL detection. The designed sensor showed a wide linear range of 0.1–35 μM with an LOD value of 0.094 μM. The interference study results reveal that the proposed material exhibits good selectivity towards CPL even in the presence of higher concentrations of interfering species. The proposed DSnO₂ matrix has been successfully utilized for real sample analysis, such as water, milk, and honey samples, with acceptable recoveries. These results closely matched with the conventional high-performance liquid chromatography data, signifying its feasibility for real-time monitoring.