High Catalytic Activity Cdots‐Based Nanozyme by Electron‐Hole Boron Heteroatom Manipulation for Multimodal Colorimetric Detection of Silver(I)

ABSTRACT 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.