High Catalytic Activity Cdots-Based Nanozyme by Electron-Hole Boron Heteroatom Manipulation for Multimodal...

Developing novel nonmetal nanozyme with high catalytic activity, environmental friendliness, and stability is challenging. In this work, a boron heteroatom-manipulated carbon-dots-based (B/Cdots) nanozyme was prepared via a simple one-step hydrothermal route. Doping of electron-hole boron could effectively downgrade their electronic energy barrier, therewith enhancing the electron transfer kinetics, and thereby promoting their peroxidase (POD)-like activity. Such POD-like activity of the B/Cdots can oxidize the colorless reduced 3,3',5,5'-tetramethylbenzidine (TMB) to its blue oxidized state, oxTMB. Benefiting from the robust affinity of glutathione of antioxidant for silver(I) (Ag^I), the B/Cdots-based colorimetric platform was constructed for Ag^I monitoring, and displayed a good linearity from 0.5 to 140 µM with a limit of detection of 0.23 µM. Excitingly, the color alteration caused by Ag^I can also be easily observed by the naked eye and smartphone imaging, achieving convenient real-time onsite monitoring and eliminating the reliance on complex instruments or specialized expertise. Beyond developing a straightforward and robust multimodal method for Ag^I analysis, this work also enriches the extant inventory of nanozymes available for colorimetric assays and related fields.