Study on performance of mimic uricase and its application in enzyme-free analysis

Nanozymes were the novel research field to replace natural enzymes because of stability and low cost. However, the research on nanozymes was mainly focused on peroxidase, and there was little research about nanozymes with oxidase-like activity, especially mimic oxidase of small molecules related to human physiology. High levels of uric acid (UA) in the body can cause hyperuricemia and gout. And natural uricase cured this disease because it could oxidize UA. The oxidase-like activity of mixed valence state metal organic frameworks with cerium (MVSM) had been studied, but MVSM was found to have uricase-like activity in this article. The catalytic process of UA with MVSM was studied by a variety of analytical methods, which was similar to the natural uricase except for further oxidation of H₂O₂. The catalytic activity constants of MVSM were acquired by the Michaelis-Menten equation. MVSM had a better ability to catalyze UA in in vivo and in vitro experiments. An enzyme-free analysis-based mimic uricase for UA was established. All the experimental results proved that MVSM had a good prospect to replace the natural uricase. A nanomaterial, mixed valence state Ce-MOF (MVSM), with uricase-like activity has been found in vivo and in vitro. This material has potential to be a fluorescent analysis for detecting uric acid without uricase.