Pt-Au Dendritic Nanoparticles with High Oxidase-like Activity for Detection of Ascorbic Acid

Due to high stability and sensitivity, inorganic nanomaterials with enzyme-like activity have brilliant application prospects. Tuning the enzyme-like activity plays great significance for promoting the development of nanozymes. In this work, Pt-Au dendritic nanoparticles (Pt-Au DNPs) with good uniformity and stability were synthesized by a simple liquid phase reduction method, and used to colorimetrically detect ascorbic acid (AA) by using their oxidase-like activity to catalyze the oxidation of TMB (3,3,5,5-tetramethylbenzidine). The oxidase-like activity was found to be highly influenced by the composition and structure of Pt-Au dendritic nanoparticles, and the relationship between kinetic parameters and nanoparticle structure was investigated. Quantitative analysis of ascorbic acid in the 1-15 mol/L range was performed with good linear relationship, and the detection limit was 78 nmol/L. At the same time, it's found that continuous reaction would reduce the catalytic performance of Pt-Au DNPs, but still has the potential to be reused, which is not common. Data from this research not only suggests a method for synthesizing Pt-Au DNPs, but also shows its potential for AA analysis in biological samples.