Electrocatalytic Reduction of Antibiotic Drug Metronidazole by Green‐Synthesized Silver Nanoparticle–Doped Chitosan

Abstract Metronidazole (MET) detection in the human body is essential for monitoring therapeutic levels, ensuring accurate dosage, and preventing toxicity or treatment failure. To facilitate this, an electrochemical (EC) sensor is developed by modifying a glassy carbon electrode (GCE) with chitosan (CS) and silver nanoparticles. Silver nanoparticles are synthesized using environmentally friendly green method, involving green tea ( Camellia sinensis ) leaf extract under microwave irradiation. These nanoparticles are combined with the biodegradable and electroactive natural polymer CS to enhance the analytical performance of the sensor. Cyclic voltammetry analysis of the modified sensor reveals an enhanced reduction peak for MET at −0.397 V, with a maximum current of −0.264 mA observed at pH 1. The EC reduction reaction is controlled by both diffusion and adsorption processes. The sensor demonstrates a linear response to MET concentrations ranging from 0.1 to 1244 µ M, with a detection limit of 0.597 nM. Additionally, it exhibits impressive stability during repeated scans and extended time periods, while its sensitivity is thoroughly evaluated through real sample analyses.