Synergistic electrochemical sensing platform for simultaneous detection of chloramphenicol and sulfamethoxazole in food samples

The sensitive detection of antibiotic residues in food is crucial due to their potential threats to human health, including antimicrobial resistance and toxic effects. In this study, a novel ZIF-67/La 2 (WO 4 ) 3 nanocomposite was synthesized via an ultrasonic assisted method and its structure and morphological properties were characterized comprehensively. The composite was employed to construct a highly sensitive electrochemical sensor for the simultaneous detection of chloramphenicol (CHL) and sulfamethoxazole (SMZ). Under optimized conditions, the sensor demonstrated a wide linear detection range of 0.01–600 μM for CHL and 0.01–200 μM for SMZ, with remarkably low detection limits of 3.43 nM (CHL) and 9.21 nM (SMZ). Detailed reaction mechanistic studies were also revealed. In addition, the constructed electrode exhibited excellent selectivity, reproducibility, and long-term stability. The recovery rates of CHL in egg and orange juice were 98.30 %–106.00 % and 96.00 %–102.00 %, respectively, with relative standard deviations (RSDs) of 2.43 % and 2.12 %. The recovery rates of SMZ in egg and orange juice samples were 96.00 %–112.30 % and 94.00 %–103.00 %, respectively, with RSDs of 2.73 % and 2.81 %. This work not only establishes a reliable analytical method for antibiotic monitoring but also provides fundamental insights into the electrochemical sensing mechanisms, paving the way for future development of advanced detection systems in food safety. • Novel ZIF-67/La 2 (WO 4 ) 3 sensor detects CHL and SMZ simultaneously with ultra-low LODs. • Synergistic nanocomposite enhances electron transfer, achieving wide linear ranges. • High recovery rates in food samples validate practical applicability for food safety.