Nanoenzyme is a kind of mimic enzyme with unique properties of nanomaterials and catalytic function. They have been developed to address the limitations of natural enzymes and conventional artificial enzymes. Compared with traditional mimic enzymes, nanoenzymes have the advantages of higher catalytic efficiency, low costs, high stability against stringent reaction conditions. The catalytic reaction of nanoenzymes is the same as natural enzymes, which depends on pH, temperature and substrate concentration. Taking advantage of the high catalytic properties of bimetallic alloy nanoparticles, we prepare Au@Pt nanoparticles with high catalytic activity and use it to detect ascorbic acid. As a mimic oxidase, Au@Pt nanoparticles shows the good biocompatibility of Au@Pt nanoparticles for promising bioapplications[1].