A ternary AuNP/NiFe-LDH/MWCNT heterostructure enhanced electrochemical biomimetic sensor for sensitive detection of enrofloxacin in aquatic foods

The development of sensitive and selective electrochemical sensors for antibiotic detection is critical to ensuring food safety. Herein, we report a novel biomimetic electrochemical sensor using a ternary AuNP/NiFe-LDH/MWCNT heterostructure combined with molecularly imprinted polymers (MIPs) for detecting enrofloxacin (ENR) in food. The AuNP/NiFe-LDH/MWCNT composite was prepared by in-situ reducing HAuCl 4 on a NiFe-LDH/MWCNT backbone, forming a heterojunction structure that enhances charge separation and electron transfer. Electropolymerization of pyrrole with ENR produced highly selective MIP layers. The synergistic integration of high conductivity, abundant catalytic sites, and selective molecular recognition endows the sensor with excellent electrochemical performance. The sensor exhibits a wide linear range (0.05–100.0 μM) and an ultralow limit of detection (LOD) 0.025 μM. It showed superior selectivity, reproducibility, stability, and applicability in complex aquatic food samples, with recoveries of 94.6 % to 103.9 %. This work paves the way for practical, high-precision monitoring of trace antibiotics in food safety applications.