Glucose-oxidase like catalytic mechanism of noble metal nanozymes

Abstract

Au nanoparticles (NPs) have been found to be excellent glucose oxidase mimics, while the catalytic processes have rarely been studied. Here, we reveal that the process of glucose oxidation catalyzed by Au NPs is as the same as that of natural glucose oxidase, namely, a two-step reaction including the dehydrogenation of glucose and the subsequent reduction of O2 to H2O2 by two electrons. Pt, Pd, Ru, Rh, and Ir NPs can also catalyze the dehydrogenation of glucose, except that O2 is preferably reduced to H2O. By the electron transfer feature of noble metal NPs, we overcame the limitation that H2O2 must be produced in the traditional two-step glucose assay and realize the rapid colorimetric detections of glucose. Inspired by the electron transport pathway in the catalytic process of natural enzymes, noble metal NPs have also been found to mimic various enzymatic electron transfer reactions including cytochrome c, coenzymes as well as nitrobenzene reductions.

Live microalgal cells modified by L‐cys/Au@carbon dots/bilirubin oxidase layers for enhanced oxygen reduction in a membrane‐less biofuel cell

“…Besides, the power density indicated that the performance of ACB@algae biofuel cell was 2.1 times and 2.39 times higher than that of ACB or BOD biofuel cells in the O 2 saturated solution, respectively. It should be noted that excessive O 2 may diffuse to the anode to hinder the glucose oxidation reaction by accepting the electrons from the Au NPs 54 . While for the ACB@algae biofuel cell, the strategy of O 2 ‐generated in situ leads to low O 2 concentration in electrolyte.…”

“…It should be noted that excessive O 2 may diffuse to the anode to hinder the glucose oxidation reaction by accepting the electrons from the Au NPs. 54 While for the ACB@algae biofuel cell, the strategy of O 2 -generated in situ leads to low O 2 concentration in electrolyte. These results showed that the electrocatalytic ORR performance with the ACB@algae cathode is not only superior to pure BOD biofuel cell fed by O 2 bubbling, but also very competitive with previously reported BFC using native microalgal cells (Table S1).…”

Nanozymes-recent development and biomedical applications

“…Enzymatic properties of gold nanoparticles (Au NPs) have widespread uses in biomedical applications [ 110 ]. Many studies have reported that Au NPs exhibited multiple-enzymes mimicking abilities such as peroxidase-mimetic activity and glucose oxidase (GOD) activity [ 111 – 113 ]. The GOD-like activity of Au nanoparticles can deplete the glucose and generate H 2 O 2 , which could effectively consume glucose nutrients and inducing cell starving in tumor tissues.…”

Research Progress and Prospects of Nanozyme-Based Glucose Biofuel Cells

“…For the GOx-mediated oxidation of one glucose molecule, two electrons are formed by the production of one gluconolactone and one H 2 O 2 . Based on the high research and application significance, diverse types of nanomaterials comprising noble metals and metal oxides have been studied as GOx-mimicking nanozymes [ 35 , 36 , 37 , 38 , 39 ]. Among them, gold nanoparticles (Au NPs) have been a focus of investigation, and interestingly, their glucose oxidation mechanism was proposed to be the same as that of natural GOx [ 35 ], which is highly affected by morphological features, including size, and reaction environments, including temperature, pH, and reaction time [ 37 ] ( Figure 2 ).…”

“…Based on the high research and application significance, diverse types of nanomaterials comprising noble metals and metal oxides have been studied as GOx-mimicking nanozymes [ 35 , 36 , 37 , 38 , 39 ]. Among them, gold nanoparticles (Au NPs) have been a focus of investigation, and interestingly, their glucose oxidation mechanism was proposed to be the same as that of natural GOx [ 35 ], which is highly affected by morphological features, including size, and reaction environments, including temperature, pH, and reaction time [ 37 ] ( Figure 2 ). Interestingly, the GOx-like activity of Au NPs was further improved by utilizing a molecularly imprinted polymer functionalized on their surface, resulting in a 270-fold higher catalytic activity than that of bare Au NPs [ 39 ].…”