Solving the H2O2 by-product problem using a catalase-mimicking nanozyme cascade to enhance glycolic acid oxidase

Self-inactivation of oxidases due to by-product hydrogen peroxide (H 2 O 2 ) is a main obstacle to applying these enzymes in chemical production. Herein, we report an efficient cascade strategy of co-immobilizing a natural oxidase and catalase-mimicking coordination nanoparticles. Fe 3+ and adenosine monophosphate (AMP) formed coordination nanoparticles with comparable performance as natural catalase at ambient conditions for degrading H 2 O 2 , but the former still maintained about 90% or 75% catalytic activity after pH 2.0 or 90 °C treatment, respectively. Upon polymerization with a few acrylic monomers, glycolic acid oxidase (GyAO) was co-immobilized with Fe 3+ /AMP within a nanogel. Benefiting from the confinement and protection effect of the nanogel, the catalytic activity increased by 5-fold at pH 4, and 10-fold at 80 °C, and the catalytic activity of the nanogel still retained more than 65% after recycling 20 times. More importantly, the tolerance of the nanogel to glycolic acid enhanced 100 times compared with the free GyAO enzyme. This study has expanded the application of nanozymes to industrial catalysis, where harsh conditions are expected.