Bimetallic-doped carbon dots-driven three-mode sensor Array for tetracycline antibiotics identification.

The structural similarity of tetracycline antibiotics (TCs) makes their discrimination in complex environmental and food matrices a significant challenge. Herein, we develop a triple-signal sensor array based on a single Mn/Ce-doped carbon dot (Mn/Ce@CDs) material that uniquely integrates intrinsic fluorescence, oxidase-mimicking activity, and photothermal conversion. Using Mn/Ce@CDs as the sole sensing unit, a three-channel (fluorometric, colorimetric, photothermal) array is constructed. Differential inhibition of catalytic activity and fluorescence quenching by four TCs (tetracycline, chlortetracycline, oxytetracycline, doxycycline) generates compound-specific response fingerprints. Combined with linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA), the array achieves accurate discrimination of individual TCs and their mixtures, with excellent anti-interference capability against common interferents. The method is successfully applied to sewage water, milk, and honey samples, demonstrating its practical potential for multiplex antibiotic analysis in food and environmental safety monitoring.