Horseradish peroxidase (HRP) and glucose oxidase (GOX) based dual-enzyme system: Sustainable release of H2O2 and its effect on the desirable ping pong bibi degradation mechanism

In this study, an adaptable HRP/GOX-Glu system was established due to the trait, efficient degradation of pol-lutants in the catalytic process of HRP named the ping-pong bibi mechanism and a sustained release of H2O2 in -situ under the catalysis of glucose oxidase (GOX). Compared with the traditional HRP/H2O2 system, the HRP was more stable in the HRP/GOX-Glu system based on the feature of persistent releasing H2O2 in-situ. Simulta-neously, the high valent iron was found out to give a greater contribution to Alizarin Green (AG) removal through ping-pong mechanism, whereas the hydroxyl radical and superoxide free radical generated by Bio-Fenton were also the main active substances for AG degradation. Furthermore, on the basis of effect evalua-tion of the co-existence of two different degradation mechanisms in the HRP/GOX-Glu system, the degradation pathways of AG were proposed. Moreover, the optimum reaction conditions preferentially triggering ping-pong bibi mechanism instead of Bio-Fenton were determined by single factor analysis and degradation mechanism elaboration. This study would provide a reference for how to give full play to the advantages of ping-pong bibi mechanism in the dual-enzyme system based on HRP to degrade pollutants with high efficiency.

Automated summary

An adaptable HRP/GOX-Glu system was established in this study, which achieved efficient degradation of pollutants through the ping-pong bibi mechanism of HRP and sustained release of H2O2 catalyzed by glucose oxidase (GOX). The HRP/GOX-Glu system showed higher stability compared to the traditional HRP/H2O2 system due to the persistent release of H2O2 in-situ. The study also identified the contributions of high valent iron, hydroxyl radical, and superoxide free radical in the removal and degradation of Alizarin Green (AG).