An efficient electrochemical sensor based on ZIF-8 MOF-derived N-containing porous carbon supported Fe3O4 nanoparticles for sensitive detection of ciprofloxacin residues in foods

The indiscriminate use and excessive consumption of ciprofloxacin (CIP) may induce adverse effects in both humans and animals, while concurrently contributing to environmental contamination. Hence, there is an urgent demand to establish highly efficient detection methods for trace ciprofloxacin residues. Herein, a highly efficient electrochemical sensor based on ZIF-8 metal-organic framework (MOF)-derived N-containing porous carbon-supported Fe 3 O 4 nanoparticles (Fe 3 O 4 /NPC) was fabricated for the sensitive determination of CIP residues in milk and honey. Due to the synergistic interaction between Fe 3 O 4 NPs and NPC, the composite exhibited large specific surface area, high conductivity, and abundant internal catalytic sites, effectively improving the voltammetric response of CIP. As a result, the Fe 3 O 4 /NPC demonstrated significant electrocatalytic activity for CIP oxidation, with two wide linear response ranges (0.01–1.0 μM and 1.0–10 μM), high sensitivity (3.312 and 0.8574 μM μA −1 ), and a low limit of detection (0.002 μM). The Fe 3 O 4 /NPC/GCE showed strong anti-interfering capabilities even in excess potential interference substances, and could operate stably for at least one month (with a current retention rate of 81.9 %). Moreover, the Fe 3 O 4 /NPC/GCE was successfully applied to the determination of CIP in milk and honey, achieving satisfactory recovery (95.2 %–103.8 %). Considering its significant advantages such as cost-effectiveness, ease of operation, and excellent sensing properties, the Fe 3 O 4 /NPC has broad application prospects on sensitive detection CIP residues at trace level.