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

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 H 2 O 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 Se 0 to Se δ+, 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.