Single‐Atom Catalysts in Catalytic Biomedicine

Abstract

The intrinsic deficiencies of nanoparticle‐initiated catalysis for biomedical applications promote the fast development of alternative versatile theranostic modalities. The catalytic performance and selectivity are the critical issues that are challenging to be augmented and optimized in biological conditions. Single‐atom catalysts (SACs) featuring atomically dispersed single metal atoms have emerged as one of the most explored catalysts in biomedicine recently due to their preeminent catalytic activity and superior selectivity distinct from their nanosized counterparts. Herein, an overview of the pivotal significance of SACs and some underlying critical issues that need to be addressed is provided, with a specific focus on their versatile biomedical applications. Their fabrication strategies, surface engineering, and structural characterizations are discussed briefly. In particular, the catalytic performance of SACs in triggering some representative catalytic reactions for providing the fundamentals of biomedical use is discussed. A sequence of representative paradigms is summarized on the successful construction of SACs for varied biomedical applications (e.g., cancer treatment, wound disinfection, biosensing, and oxidative‐stress cytoprotection) with an emphasis on uncovering the intrinsic catalytic mechanisms and understanding the underlying structure–performance relationships. Finally, opportunities and challenges faced in the future development of SACs‐triggered catalysis for biomedical use are discussed and outlooked.

The Coppery Age: Copper (Cu)‐Involved Nanotheranostics

“…[1][2][3][4][5][6][7] This interdisciplinary field also promotes the concomitant development of new theranostic modalities on combating diverse diseases, where an overwhelming upsurge of nanomaterials is the fundamental/crucial basis and prerequisites determining the final theranostic performance. [8][9][10][11][12][13] Organic nanosystems have been extensively explored in nanomedicine, in accompany with clinically relevant family members entering the clinical stage. [14][15][16][17][18][19][20] Comparatively, inorganic nanomaterials are mainly created in the past decade with noticeable advances very recently.…”

Atomic engineering of single-atom nanozymes for enzyme-like catalysis

“…Integrated with the intrinsic structural and physicochemical properties simultaneously, the emerging SAzymes will undoubtedly boost the crucial applications of nanozyme technologies. 67,69,101 For instance, in vivo and in vitro bioassays, such as H 2 O 2 , glucose, ascorbic acid, and glutathione, are the most extensive and essential applications of nanozymes. The detection sensitivity could be signicantly improved benetting from the ultrahigh activity of SAzymes, and specic detections could be realized by the SAzymes with sole enzyme activity.…”

Improving the Catalytic Activity of Carbon‐Supported Single Atom Catalysts by Polynary Metal or Heteroatom Doping

“…Some catalytic properties of SACs are even higher than that of commercial catalysts. Apart from above electrochemical reactions, carbon‐based SACs have begun to be used in many photocatalysis organic synthesis, and versatile biomedical applications, [ 108,109 ] for example, Pd‐NC SACs (single‐atom Pd on N‐doped graphene) show high selectivity in photothermal hydrogenation of acetylene to ethylene; [ 110 ] Fe‐NC SACs (Fe‐N x C y catalytic sites on carbon) have high activity and selectivity in catalytic oxidation of benzene to phenol [ 62 ] and Zn‐NC SACs (single‐atom Zn on N‐doped carbon) can suppress the bacteria proliferation and facilitate the wound regeneration due to their predominant peroxidase‐mimicking activity. [ 111 ] However, there is no doubt that there is always great potential for the development of carbon‐supported SACs, which raises a question of how to effectively and accurately regulate metal catalytic sites for preparing low‐cost SACs with high activity, stability, and selectivity.…”