Single‐Atom Nanozymes for Biomedical Applications: Recent Advances and Challenges

Abstract

Nanozymes have received extensive attention in the fields of sensing and detection, medical therapy, industry, and agriculture thanks to the combination of the catalytic properties of natural enzymes and the physicochemical properties of nanomaterials, coupled with superior stability and ease of preparation. Despite the promise of nanozymes, conventional nanozymes are constrained by their oversized size and low catalytic capacity in sophisticated practical application environments. single-atom nanozymes (SAzymes) were characterized as nanozymes with high catalytic efficiency by uniformly distributed single atoms as catalysis sites, thus effectively addressing the defects of conventional nanozymes. This paper reviews the activity improvement scheme and catalytic mechanism of SAzymes and highlights the latest research progress of SAzymes in the fields of biomedical sensing and therapy. Eventually, the challenges and future directions of SAzymes are discussed in this paper.

Emerging antibacterial nanozymes for wound healing

“…49 Swiftly, many SAzymes, including single-atom Pd nanozyme, single-atom Fe-containing nanozyme, and Fe-N-C nanozyme, were studied in environmental protection, medical treatment, and sensing. [50][51][52] In this section, we summarized some antibacterial SAzymes for treating wound infection.…”

“…In recent studies, other metal-based SAzymes were explored for the biomedical field, and some of them were studied for wound disinfection applications. 47,48,52,[54][55][56][57] Xu et al fabricated single-atom iron nanozymes for bacteria-infected wound administration. 54 The iron SAzyme with the POD-mimic activity could generate •OH by adding H 2 O 2 and showed NIR photothermal performance for producing heat and glutathione oxidization.…”

A Single‐Atom Nanozyme Cascade for Selective Tumor‐Microenvironment‐Responsive Nanocatalytic Therapy

“…Nanomaterial‐induced in situ chemical reactions for initiating cell apoptosis by catalyzing certain chemical reactions have been greatly explored for tumor‐specific therapies [10] . However, the discovery of single‐atom nanozymes marked a significant contribution to the area of nanozymes that endows them with enriched active sites, diverse enzyme‐like behavior, and an understanding of the underlying mechanism [11–13] . In this regard, single‐atom catalysts promoting the atom economy with ample active sites and remarkable catalytic efficiency are currently in trend.…”

“…[10] However, the discovery of single-atom nanozymes marked a significant contribution to the area of nanozymes that endows them with enriched active sites, diverse enzyme-like behavior, and an understanding of the underlying mechanism. [11][12][13] In this regard, single-atom catalysts promoting the atom economy with ample active sites and remarkable catalytic efficiency are currently in trend. Moreover, modulating the coordination environment further endows them with superior catalytic activity and stability.…”

Nanozymes Based on MXene Nanosheets Decorated with Pt Nanoparticles for Hyperthermal-Enhanced Cascade Catalytic Therapy of Tumors

“…Realizing efficient and less toxic treatments for cancer is always the focus of research . Together with the development of nanomedicine, nanocatalytic therapy provides new perspectives for the treatment of cancer. , Catalytic therapy mainly involves a chemical reaction in situ within the tumor with catalytically active nanomaterials to produce toxic substances to kill tumor cells. , Nanozymes are attracting widespread attention in the field of catalytic medicine since they contain the catalytic activity of natural enzymes and the physicochemical properties of nanomaterials. − In recent years, multiple nanozymes are emerging, including carbon-based nanozymes, iron-based nanozymes, manganese-based nanozymes, , and single-atom nanozymes, − which are widely used for detection, disease therapy, and especially nanozyme-mediated tumor catalytic therapy. − …”