Daptomycin templated bimetallic PdPt3 nanoparticles with peroxidase-like and oxidase-like activities for sensitive colorimetric detection of glutathione in milk and fruit juice

The convenient and reliable detection of glutathione is beneficial to the human body. The colorimetric detection method based on nanozyme is accurate and easy to operate. However, there are still problems with the improvement in the activity and stability of nanozyme, as well as the rational construction of colorimetric platform. Herein, daptomycin templated PdPt3 nanoparticles (PdPt3-Dap NPs) were prepared with a size of 2.46±0.11 nm. PdPt3-Dap NPs were demonstrated to possess peroxidase-like and oxidase-like activities and the dual-enzymatic activities were improved through the regulation of Pd and Pt ratio. Besides, the unique amphipathic structure of Dap conferred the stability to PdPt3-Dap NPs in detection applications. The peroxidase-like mechanism of PdPt3-Dap NPs was to catalyze the generation of •OH from H2O2. The oxidase-like mechanism was to catalyze the generation of superoxide anions(•O2-) and singlet oxygen(1O2) from dissolved oxygen. Because oxidase activity reduces interference from additional hydrogen peroxide, a colorimetric detecting method for glutathione was established based on the oxidase-like activity of PdPt3-Dap NPs. The linear range of the proposed detecting method for glutathione was 0–400 μM and the low limit of detection was 2.56 μM. The detecting method had been successfully applied in detecting glutathione in food samples with a recovery range between 92.20 % and 107.27 %. which showed a good prospect for detecting glutathione in practical applications. [Display omitted]