Cluster-Induced Hydrogen Bonding Boosts Catalysis of Se Single-Atom/Cluster Nanozyme for Intelligent Water Quality...

Intelligence and bionics are key directions for next-generation sensors, yet achieving dynamic adaptability remains challenging. Inspired by natural enzymes like chymotrypsin, this work synthesizes a N-doped graphyne-based composite nanozyme (Se-2NGY) featuring selenium (Se)-single atoms and cluster sites. Biologically active Se-single atoms act as the primary catalytic center, while nearby clusters reduce the energy and stabilize the configuration by inducing the formation of hydrogen bonds with H2O molecules. This synergistic architecture delivers excellent peroxidase (POD)-like activity. Density functional theory calculations confirm the clusters' role in modulating the p-band center and reducing the energy barrier. A key innovation is that the POD-like activity can be finely tuned by UV-light exposure. In-situ characterizations reveal that photoexcitation converts Se0 to Seδ+, generating more hydroxyl radicals and enhancing catalytic performance. Leveraging this unique photoresponsive activity, we develop a proof-of-concept, intelligent colorimetric sensor for water quality monitoring, specifically targeting thiosulfate detection. By simply adjusting light intensity, the sensor's detection range and sensitivity can be dynamically and rapidly modulated─analogous to an artificial iris─enabling flexible adaptation to environmental samples with vastly different pollutant concentrations. This work provides a high-performance nanozyme design strategy and pioneers a pathway toward light-controllable, intelligent sensing systems for real-world environmental monitoring.