Application of carbon quantum dots as fluorescent probes in the detection of antibiotics and heavy metals

Carbon quantum dots (CQDs) are ideal fluorescent probes for rapid detection. This paper reviews the synthesis methods of CQDs, their application in the rapid detection of antibiotics and heavy metals in the environment and food, and the underlying detection mechanisms. The hydrothermal method is the most commonly used for synthesis, and CQDs doped with heteroatoms (such as N, P and S) exhibit superior fluorescence performance. In the presence of antibiotics and heavy metals, the fluorescence of CQDs can be quenched or enhanced. Single-signal and dual-signal probes can be developed using the fluorescence, phosphorescence and absorbance of CQDs, enabling rapid detection of various antibiotics (e.g., tetracycline, quinolone and beta-lactam antibiotics) and heavy metals (e.g., Cd²⁺, Cr⁶⁺, Fe³⁺, Hg²⁺, and Pb²⁺). With the combination of smartphones and fluorescent probe test strips developed based on CQDs, on-the-spot rapid detection can be realized. This review offers new insights into the rapid detection of CQDs.