The Rational Design of Pt Single Atoms-Bridged Nanozyme with Enhancing Direct Electron Transfer Pathway for Glucose Oxidation

Abstract

Nanozymes are promising tools in chemical synthesis, environmental remediation, and diagnostic sensing owing to their enzyme-like catalytic properties. However, the inherent limitations of nanozymes stemming from their biological catalytic pathway dependency have fundamentally hindered their broader application. In this work, nanozyme with a direct electron transfer mechanism, mimicking natural glucose oxidase for glucose oxidation, is synthesized to offer a stable and direct catalytic pathway. Theoretical and experimental results demonstrate that Pt single atom sites on the nanozyme trigger robust metal-support interaction for Au nanoparticles, forming a positively charged region on the Au surface. As a result, the Au could directly capture electrons from the oxygen atom in glucose to form the self-powered electrochemical signal through direct electron transfer pathway, which is distinct from the common cascade reaction pathway for glucose oxidase. Herein, a self-powered sensor based on a microfluidic chip is fabricated, showing high sensitivity for the detection of glucose with a detection limit of 10 nm. Its successful application in the detection of glucose in blood and real human sweat samples, and also a real-time detection of glucose in sweat during the cycling and running offers insights into nanozyme innovations and provides promising commercialization potentials for noninvasive testing.