Ultrasensitive photoelectrochemical sensing of enrofloxacin based on CuFe2O4/Znln2S4-Z-type heterojunction.

A novel composite material was innovatively applied in photoelectrochemical sensing, by leveraging the large specific surface area of ZnIn2S4. CuFe2O4 was anchored onto ZnIn2S4 to improve its poor dispersibility, forming a Z-scheme heterojunction with enhanced charge separation and preserved strong redox capability. A signal-off photoelectrochemical sensor was constructed where enrofloxacin (ENR) uniquely serves as both the target and electron-consuming agent. The sensor exhibits a wide detection range from 1 × 10⁻15 M to 1 × 10⁻9 M, with an exceptionally low detection limit of 0.78 fM. The sensor demonstrated outstanding performance in the testing of milk, honey, and chicken samples, confirming its potential for practical applications in environmental and biological sample analysis.