Current Advances on the Single‐Atom Nanozyme and Its Bioapplications

Abstract

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 nanomaterial‐initiated catalysis compared with the natural enzymes promote the pursuing 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. Here, focus is mainly on the three parts. First, 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 antibacterial/antiviral performance, cancer therapy, and biosensing) are highlighted. In the end, the future perspective and challenge facing are demonstrated.

Perspectives on Usage of Functional Nanomaterials in Antimicrobial Therapy for Antibiotic-Resistant Bacterial Infections

“…Nanozymes can perform various enzyme-like functions in different areas, such as regulating biomolecular and cellular pathways, cleaving proteins or poly nucleic acids, modulating oxidative balance, and performing site-specific cleavage of prodrugs. , These functions make nanozymes useful in different applications, including therapeutics, regenerative medicine, diagnostics, and preservation. Endogenous enzymes in the cell catalyze metabolic events and produce hazardous ROS that potentially kills the bacterial cell membranes and intracellular components by oxidation .…”

Development of nanozyme based sensors as diagnostic tools in clinic applications: a review

“…With their high surface area, outstanding stability, flexibility with dopants, and excellent electrical conductivity, carbon-supported single atoms (SACs such as M–N–C) show significant potential in the catalysis field. 66 Like the active sites of oxymyoglobin, HRP, and cytochrome P450 enzymes, each has a single heme Fe with a proximal ligand. 67 FeN 4 (M–N–C) in iron-based single-atom NZs serves the same purpose.…”

Dimensionality Engineering of Single-Atom Nanozyme for Efficient Peroxidase-Mimicking

“…Single-atom nanozymes featuring well-defined M–N x (M = Fe, Co, Pt, Mn, and Cu) sites are new enzyme-mimicking candidates, which have been widely applied in tumor therapy, disinfection, and other fields. − The maximum atom utilization and similarity of M–N x sites to those of natural metalloenzymes endow SAzymes with a higher catalytic activity than conventional nanozymes. − However, they have a limited catalytic activity compared to natural enzymes, which restricts their performance and further application. Recently, the manipulation of the surrounding atomic configuration of SAzymes has been widely adopted to improve their catalytic activity. − For example, the catalytic performance of SAzymes can be regulated by tuning the coordination numbers of the single metal sites. − Likewise, replacing coordinated nitrogen with other elements to form Fe/CoN 3 P or FeN 3 S could enhance enzyme-like activity via near–range interactions. − Heteroatom doping (for example, with phosphorus and boron) of the carbon matrix can also enhance the peroxidase-like (POD-like) activity of the Fe center through long–range interactions. , Despite the significant advances made, the active sites in SAzymes are still generally two-dimensional (2D) and isolated catalytic units.…”