Tuning Local Coordination Environments of Manganese Single‐Atom Nanozymes with Multi‐Enzyme Properties for Selective Colorimetric Biosensing

Abstract

Single‐atom nanozymes (SAzymes) are promising in next‐generation nanozymes, nevertheless, how to rationally modulate the microenvironment of SAzymes with controllable multi‐enzyme properties is still challenging. Herein, we systematically investigate the relationship between atomic configuration and multi‐enzymatic performances. The constructed MnSA−N3‐coordinated SAzymes (MnSA−N3−C) exhibits much more remarkable oxidase‐, peroxidase‐, and glutathione oxidase‐like activities than that of MnSA−N4−C. Based on experimental and theoretical results, these multi‐enzyme‐like behaviors are highly dependent on the coordination number of single atomic Mn sites by local charge polarization. As a consequence, a series of colorimetric biosensing platforms based on MnSA−N3−C SAzymes is successfully built for specific recognition of biological molecules. These findings provide atomic‐level insight into the microenvironment of nanozymes, promoting rational design of other demanding biocatalysts.

Epoxy‐rich Fe Single Atom Sites Boost Oxygen Reduction Electrocatalysis

“…The hypothesis was demonstrated by further evaluating the ORR performance of Fe1/NSOC in 0.1 M KOH solution containing 10 mM of KSCN, which is capable of binding with the metal species, thus lowering the corresponding catalytic activity during electrocatalysis. [37,38] As shown in Figure S15, the ORR performance of Fe1/ NSOC decreases after the incorporation of KSCN, with the E 1/2 negative shift of 40 mV. This reveals that the Fe single atom sites are the active sites for ORR, while the surrounding environment (epoxy and S groups) helps to boost the performance (Figure 3a).…”

“…The superior catalytic activity of Fe1/NSOC over NSC suggests that the Fe species could be the active sites for oxygen reduction. The hypothesis was demonstrated by further evaluating the ORR performance of Fe1/NSOC in 0.1 M KOH solution containing 10 mM of KSCN, which is capable of binding with the metal species, thus lowering the corresponding catalytic activity during electrocatalysis [37,38] . As shown in Figure S15, the ORR performance of Fe1/NSOC decreases after the incorporation of KSCN, with the E 1/2 negative shift of 40 mV.…”

Epoxy‐rich Fe Single Atom Sites Boost Oxygen Reduction Electrocatalysis

“…The hypothesis was demonstrated by further evaluating the ORR performance of Fe1/NSOC in 0.1 M KOH solution containing 10 mM of KSCN, which is capable of binding with the metal species, thus lowering the corresponding catalytic activity during electrocatalysis. [37,38] As shown in Figure S15, the ORR performance of Fe1/ NSOC decreases after the incorporation of KSCN, with the E 1/2 negative shift of 40 mV. This reveals that the Fe single atom sites are the active sites for ORR, while the…”

Single-atom catalysts: promotors of highly sensitive and selective sensors

“…8a). 108 The Mn–N 3 –C complex shows higher oxidase-, peroxidase- and glutathione oxidase-like activities than Mn–N 4 –C (Fig. 8b and c).…”