A novel triple-mode sensor utilizing trimetallic derived fluorescent carbon dots nanozyme for tetracycline...

Tetracycline (TC) is notoriously resistant to degradation in natural environments, which contributes to its prolonged persistence and widespread contamination. Improper or excessive use of TC can lead to multifaceted hazards. In this study, we developed a trimetallic-doped carbon dots (Fe,Cu,Ce-CDs)-based composite that exhibits distinct fluorescence and peroxidase-like activity, facilitating triple-mode detection of TC. The results indicate that TC significantly influences the signals of both the catalytic system and fluorescence intensity. Notably, the material itself can react with TC to produce a brown coloration. This sensor eliminates the need for complex aptamers or antibodies, thus bypassing cumbersome reaction processes and synthesis-related losses, enabling straightforward TC detection. The signal demonstrates a linear relationship with TC concentration in the range of 6.67 ng/mL to 667.67 μg/mL, yielding satisfactory detection sensitivity (LOD = 0.26 ng/mL) among the three modes. The practical application validation was performed using milk and chicken samples, achieving recovery rates ranging from 90.6% to 105.5%. This accuracy and reliability affirm the feasibility of this method for monitoring TC content in food matrices.