Axially Coordinated Gold Nanoclusters Tailoring Fe-N-C Nanozymes for Enhanced Oxidase-Like Specificity and Activity

Metal-organic frameworks (MOF) derived nitrogen-doped carbon-supported monodisperse Fe (Fe-N-C) catalysts are intensively studied, but great challenges remain in understanding the relationship between the coordination structure and the performance of Fe-N-C nanozymes. Herein, a novel nanocluster ligand-bridging strategy is proposed for constructing Fe-S₁ N₄ structures with axially coordinated S and Au nanoclusters on ZIF-8 derived Fe-N-C (labeled Au_x /Fe-S₁ N₄ -C). The axial Au nanoclusters facilitate electron transfer to Fe active sites, utilizing the bridging ligand S as a medium, thereby enhancing the oxygen adsorption capacity of composite nanozymes. Compared to Fe-N-C, Au_x /Fe-S₁ N₄ -C exhibits high oxidase-like specificity and activity, and holds great potential for detecting acetylcholinesterase activity with a detection limit of 5.1 µU mL^-1 , surpassing most reported nanozymes.