Innovative dual-oxidase nanozyme sensor array for rapid detection of tetracyclines in animal-derived foods

Tetracycline antibiotics (TCs), a class of broad-spectrum antibacterial agents, are frequently detected as residues in animal-derived foods, posing a significant food safety risk. Long-term intake of TC residues can induce antimicrobial resistance, trigger allergic reactions, and cause direct toxicity, compromising human health. Conventional detection methods face challenges in analyzing complex TC contaminants in food, necessitating a high-throughput strategy for their differentiation and detection. Herein, a MnO₂/ZnNC nanozyme colorimetric sensor array with dual-oxidase activity was constructed by integrating MnO₂ with a metal-organic framework (MOF) derivative (ZnNC), enabling differentiation and sensitive detection of four TCs (tetracycline, oxytetracycline, chlortetracycline, and doxycycline). Leveraging oxidase and laccase activities, the dual-channel array generates unique chemical fingerprints for each analyte. The sensor array distinguished different tetracyclines and quantified TC with a linear range of 1-200 μM and a detection limit of 0.2242 μM. It also has similar quantitative capabilities for the other three antibiotics. Blind sample identification and differentiation in actual samples were achieved with an accuracy of 100 % and recovery rates of 90.3 %-104.5 %. This work offers a strategy for TC identification in complex systems and contributes to the design of nanozyme-based colorimetric sensor arrays.