Axial Boron Coordination Reconstructs Stereostructure of Cu Single-Atom Nanozymes for Efficient Water-Phase Chemical Sensing.

Developing single-atom nanozymes with stereoconfigurations is a new paradigm for biomimetic construction of next-generation natural enzyme alternatives and for achieving high enzyme-like selectivity and activity. This work developed a high-temperature pyrolysis tandem chemical vapor deposition technique to produce Cu SAzymes (Cu-B/N-C) with axial B coordination as laccase mimics, with Cu-BaxialN3-C as the core structure. Axial ligands modulate the d-band center of Cu SAzymes to identify the equilibrium point between the energy barriers of reactant adsorption and product desorption. Transforming product desorption from an endothermic process to a spontaneously exothermic process promotes the regeneration of nanozymes after catalytic cycles. This results in Cu-B/N-C exhibiting higher kinetic parameters and specific activity than natural laccase. Subsequently, a sensor array for high-throughput detection of phenolic pollutants in seawater was constructed based on the time-dependent changes in the laccase-like catalytic kinetics of Cu SAzymes before and after modification. On this basis, a stepwise prediction model was further developed using machine-learning artificial neural network algorithms to enhance the sensor array's detection accuracy for blind samples. Overall, this work provides new insights into the rational design of artificial enzymes from a stereochemical perspective.