Dual-emission fluorescence sensor based on biocompatible bovine serum albumin stabilized copper nanoclusters for ratio and visualization detection of hydrogen peroxide

In this work, bovine serum albumin stabilized copper nanoclusters (BSA-CuNCs) with highly red fluorescent were fast prepared by increasing the temperature in aqueous medium and used as a fluorescent probe for the sensitive detection of H2O2 in water and rat serum. Unexpectedly, the prepared BSA-CuNCs showed dual emission peaks at 450 and 620 nm, respectively, and had excellent stability such as outstanding photobleaching resistance and salt tolerance. Under optimized conditions, H2O2 can reduce the fluorescence signal at 620 nm (F620) and enhance the fluorescence signal at 450 nm (F450), meanwhile, the color of the probe changed from red to blue, resulting in ratiometric and visualization detection of H2O2 with high accuracy. F450/F620 was linearly proportional to H2O2 concentration in the ranges from 0 to 100 μM, with limit of detection 0.082 μM. In the rat serum spiked experiment, it showed a reasonable recovery rate. More importantly, cytotoxicity tests showed that BSA-CuNCs had little cytotoxicity. Therefore, the prepared BSA-CuNCs fluorescent probe has potential practical application prospects.