Self-Adapting Graphitic C6N6-Based Copper Single-Atom Catalyst for Smart Biosensors

Abstract

Self-adaptability is highly envisioned for artificial devices such as robots with chemical noses. For this goal, seeking catalysts with multiple and modulable reaction pathways is promising but generally hampered by inconsistent reaction conditions. Herein, we report a self-adaptive CuSAC6N6 single-atom catalyst having two reactive oxygen-oriented pathways under the same reaction conditions. CuSAC6N6 consisted of coordinated peroxidase-like Cu-N coordination centers and photo-responsive donor-π-acceptor (D-π-A) units with promoted intramolecular charge separation and migration. Interestingly, it drove the basic oxidation of peroxidase substrates by the bound copper-oxo pathway, and undertook a second gain reaction triggered by light via the free hydroxyl radical pathway under the same conditions. A remarkable basic activity and a superb gain of up to 3.6 times under household lights were observed, significantly higher than that of its control systems, including solo carbon nitride-based nanozymes or photocatalysts, their mixtures, and even that under thermal stimuli to the maximum endured temperature for most lives. As an application, the self-adapting CuSAC6N6 was used to construct a glucose biosensor, which can intelligently switch the linear detection range and sensitivity to a diverse range of concentrations in vitro.

Graphitic C6N6-supported Dual Cu/Zn Single-Atom Catalyst Mimicking Allosteric Regulation for Intelligent Switching Biosensing

“…5), completing the photocatalytic valence states cycle between +1 and 0. 45,75 Therefore, for Cu/Zn-C6N6, the multiformity of the cycles between different valence state for the same catalytic active center made the reaction activity capable of being highly reversible conversion, which outperformed the multi-enzyme activity of natural enzymes to a certain extent.…”

“…Growing research interest focuses on sensing these metabolites as a potential early diagnostic biomarker for disease prevention. In recent years, many nanozyme-based biosensing strategies of glucose and xanthine have been reported, 1,17,45,76,77 As a proof of concept, we proposed an intelligent switch sensor for alternatingly monitoring glucose and xanthine in a continuous flow microfluidic reactor, in which the above SOD-like and POD-like reactions would be promoted with enhanced mass transfer. Moreover, it was able to miniaturize the system, became a portable real-time monitoring platform, and simulate the basic behavior of cells.…”

“…It is worth noting that transition metal-based SAzymes could drive a biomimetic catalytic reaction via redox of metal centers, [38][39][40][41][42][43][44][45][46] which is similar to the action of natural metalloenzymes. However, the mismatch between the initial valence state of transition metal active centers and electronic structures requiring for a certain catalytic behavior generally exists in different catalytic pathways, [47][48][49][50][51][52] limiting the efficient and reversible conversion among multiple functions.…”