Bringing Cerium Oxysulfate Clusters into Nanozymes by Saturated Fatty Acid Regulation for Oxidase-like Activity

Abstract

Nanozymes have demonstrated superior properties compared to natural enzymes and traditional artificial enzymes in a variety of fields. Although significant progress has been achieved, it remains challenging to develop nanozymes with an adequate catalytic activity. Herein, we, for the first time, bring cerium oxysulfate cluster (Ce-clusters) materials into nanozyme research by a saturated fatty acid regulation strategy due to their potential catalytic activity. It is found that the saturated fatty acids can control the growth, assembly, and size of Ce-clusters in the coprecipitation process, which can enhance the oxidase-like activity of Ce-clusters. With the increase of the alkyl chain length, the catalytic activity gradually decreases because of the strengthened intermolecular interactions between fatty acids and clusters. Notably, the Ce-clusters synthesized with lauric acid present the highest oxidase-like activity among these Ce-clusters. The catalytic activity of nanozyme follows typical Michaelis−Menten kinetics, and the • O 2 − and h + are the main reactive species produced during the catalytic process. Benefiting from the excellent oxidase-like activity, the resultant nanozyme is successfully applied for reductive molecule colorimetric sensing applications. This study not only introduces Ce-clusters into nanozyme research and enriches the oxidase-mimicking nanozyme family but also provides an extremely simple strategy to enhance the catalytic activity of nanozymes, holding great promise in a wide variety of nanozyme applications.