Photoelectrochemical Detection of Enrofloxacin and Oxytetracycline in Meat Samples Based on an Aptamer-Functionalized Hierarchical Bi2S3/NH2-MIL-125 (Ti)/NH2-FeCo-BDC Dual Z-Scheme Heterojunction

The abuse and illegal overuse of enrofloxacin (ENR) and oxytetracycline (OTC) in livestock and poultry breeding pose severe threats to the food safety and the ecological environment. Conventional detection methods for ENR and OTC generally suffer from long assay time, low sensitivity and poor anti-interference ability, which can hardly meet the demand for low-cost, rapid and real-time screening of antibiotic residues in complex food matrices.,In this work, an aptamer-functionalized photoelectrochemical (PEC) sensor was constructed based on a hierarchical Bi2S3/NH2-MIL-125 (Ti)/NH2-FeCo-BDC composite. The distinctive NH2-MIL-125 (Ti)/NH2-FeCo-BDC architecture efficiently promotes interfacial charge separation and transfer, and provides abundant accessible active sites. Meanwhile, the Bi2S3 component endows the composite with excellent visible-light harvesting capability. Their synergistic effect contributes to favorable electron-hole separation efficiency and enhanced PEC performance.,Under optimized experimental conditions, the as-fabricated PEC sensor exhibits a wide linear range from 1.0×10-5-102 ng/mL, with limits of detection (LOD) of 0.228 fg/mL for ENR and 0.0229 fg/mL for OTC, respectively. The sensor effectively resists interference from proteins, inorganic ions and other matrix impurities in meat samples, and displays outstanding selectivity and stability with satisfactory spiked recoveries. Accordingly, this strategy shows promising prospects for the accurate and efficient monitoring of antibiotic residues in food safety analysis and routine quality control.