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

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.