A single-atom iron nanozyme reactor for α-ketoglutarate synthesis

Efficient removal of the by-product hydrogen peroxide (H2O2) in the oxidase-catalyzed reactions is a major challenge in biocatalysis that hinders the production of high yields of ketoacids. Here, we demonstrate the use of single-atom Fe nanozymes (SAFs) for H2O2 decomposition inspired by natural enzymes, to improve the efficiency of L-Glutamate oxidase (LGOX)-assisted catalysis for α-ketoglutarate (α-KG) synthesis. SAFs exhibit Metal-Nitrogen coordination and atomically dispersed active sites, providing superior enzyme-like activity for H2O2 decomposition. The SAFs@LGOX nanozyme-enzyme nanoreactors exhibit high catalytic efficiency due to in situ removal of H2O2 by SAFs during the deamination reaction. Additionally, SAFs enhance the pH and temperature tolerance, as well as thermal stability of LGOX. The nanoreactors achieved about 90% substrate conversion to α-KG within 2.5 h, compared to almost complete oxidation of the product in the absence of single atom Fe active sites. These findings suggest that the nanozyme-based strategy for rapid byproducts removal through mimicking enzymatic activity has promising applications in biocatalysis and may inspire the design of more effective nanozymes.