A novel fluorescent probe for H₂O₂ detection based on CdSe@ZnS quantum dots/Ag nanocluster hybrid

The selective and quantitative detection of H₂O₂ is important for its employment in physiological, environmental and industrial applications. In this paper, a sensitive and selective strategy for H₂O₂ detection was established based on the fluorescence quenching of CdSe@ZnS quantum dots (QDs) by H₂O₂-mediated etching process of Ag nanoclusters (AgNCs). In this strategy, dihydrolipoic acid (DHLA) modified AgNCs were applied as H₂O₂ response group, the existence of H₂O₂ could initiate the oxidation of AgNCs and the production of Ag⁺. CdSe@ZnS QDs are very sensitive to Ag⁺, which could give rise to the effective fluorescence quenching of CdSe@ZnS QDs. Based on this strategy, the present fluorescent assay could realize the quantification detection of H₂O₂ and the limit of detection is calculated to be 0.3 μM under the optimum conditions. Furthermore, CdSe@ZnS/AgNCs hybrid-based probe was applied to detecting H₂O₂ in milk samples and showed a good recoveries results ranged from 95.8% to 112.0%, meaning the potential applicability of this strategy.