Technological watch

Artificial enzymes designed with high catalytic efficiency and stability hold great potential to develop the promising surrogates for naturally?occurring enzymes. Nanozymes, a class of nanomaterials mimicking the function of enzymes, have aroused much attention as the candidate in diverse fields with the arbitrarily tunable features owing to the diversity of crystalline nanostructures, composition, and surface configurations. However, the uncertainty of their active sites and the lower intrinsic deficiencies of nanomaterials?initiated catalysis compared with the natural enzymes promote the pursing of alternatives by imitating the biological active centers. Single?atom nanozymes (SAzymes) maximize the atom utilization with the well?defined structure, providing an important bridge to investigate mechanism and the relationship between structure and catalytic activity. They have risen as the new burgeoning alternative to the natural enzyme from in vitro bioanalytical tool to in vivo therapy owing to the flexible atomic engineering structure. In this review, we mainly focus on the three parts including the synthesis approaches for the preparation of SAzymes, catalysis modulation strategies and biomedical applications of SAzymes. Firstly, a detailed overview of single?atom catalyst synthesis strategies including bottom?up and top?down approaches is given. Then, according to the structural feature of single atom nanocatalysts, the influence factors such as central metal atom, coordination number, heteroatom doping, and the metal?support interaction are discussed. And the representative biological applications (including anti?bacterial/anti?viral performance, cancer therapy and biosensing) are highlighted. In the end, the future perspective and challenge facing are demonstrated.This article is protected by copyright. All rights reserved