Filling in the Gaps between Nanozymes and Enzymes: Challenges and Opportunities

Abstract

Using nanomaterials to mimic the function of protein enzymes is an interesting idea. Many nanomaterials have a similar size as enzymes and they also possess catalytic activity. Over the past decade, a surge of nanozyme work has emerged, likely due to the advancement in the synthesis and characterization of inorganic nanoparticles. Many typical enzymatic reactions mimicking oxidases, peroxidases, laccases, superoxide dismutases, and catalases have been realized by simple metal oxide and metal nanoparticles. In addition, small inorganic catalysts have been loaded in nanoparticles to create another type of nanozyme. The applications of nanozymes in biosensor design, environmental remediation, and therapeutics have been demonstrated. In this Topical Review, we briefly summarize the current status of the field and then focus our attention on some important problems faced by the field. These topics include developing better nanozymes with higher activity, better substrate selectivity, and engineering enzyme-like active sites. For practical applications, reliable methods for bioconjugation of nanozymes with affinity ligands need to be achieved, but not at the cost of losing the activity of nanozymes. Finally, fundamental mechanistic studies are needed to rationally design nanozymes and to obtain key insights into a few model systems.

Single‐Atom Catalysts in Catalytic Biomedicine

“…Natural enzymes (e.g., SOD and CAT) have been considered as potential antioxidant agents that are capable of protecting cells by modulating the intracellular ROS level . Nevertheless, extremely sensitive to harsh environment conditions and easy to denature in biological milieu severely hamper their applications . Consequently, exploration of alternative catalysts to mimic antioxidative enzyme catalysts is of vital significance to facilitate their wide‐ranging applications in protecting cells from oxidative stress.…”

Intracellular Chemistry: Integrating Molecular Inorganic Catalysts with Living Systems

“…All of these reactions were performed using soluble metal catalysts inside living cells; some of the SIMCats employed were well‐defined inorganic species whereas others were generated in situ by combining free ligands with metal salts. Reactions that are promoted by heterogeneous nanozymes are excluding from our discussion . The creation of SIMCat‐promoted reactions provided new chemical tools to aid researchers working in the life sciences.…”

“…Reactionst hat are promoted by heterogeneous nanozymes are excluding from our discussion. [23] The creation of SIMCat-promoted reactions provided new chemical tools to aid researchers working in the life sciences. For example, Cowan and co-workerss howedt hat E. coli bacteria could be treated with copper aminoglycoside complexes to induce cleavage of specific RNA sequences (Scheme 2B).…”

“…enzymes, metalloenzymes, DNAzymes, and ribozymes) and heterogeneous catalysts (e.g. nanozymes) studied in the biological context.…”

“…enzymes, metalloenzymes, DNAzymes, and ribozymes) and heterogeneousc atalysts (e.g. nanozymes [23,24] ) studied in the biological context. Intracellular inorganic catalysis is an exciting research frontier.I ti sd riven partly by the recognitiont hat the immense capabilities of transition metal catalysts have been largely overlooked in the life sciences.…”