Dual-emission ratio fluorescence detection of bleomycin based on nitrogen doped graphene quantum dots@gold nanoclusters assembly

Herein, a dual-emission ratio fluorescence probe for copper ions (Cu2+)-based bleomycin (BLM) detection was established for the first time. The ratio fluorescence probe, nitrogen doped graphene quantum [email protected] nanoclusters ([email protected]), showed two well-resolved emission peaks at 440 nm and 580 nm respectively. Fluorescence intensity of AuNCs at 580 nm can be quenched by Cu2+ but restored in the presence of BLM, while fluorescence intensity of NGQDs at 440 nm remained unchanged throughout the process. The Cu2+-triggered fluorescence quenching can be attributed to aggregation-induced quenching mechanism, and the strong affinity between Cu2+ and BLM can make the quenched fluorescence turn on. Under optimal conditions, the BLM can be detected in the range of 0.8–1800 nM and the limit of detection (LOD) was 0.27 nM. Furthermore, the established method in the application of human serum samples has been confirmed.