In situ growth of gold nanoparticles on hydrogen-bond supramolecular structures with high peroxidase-like activity at neutral pH and their application to one-pot blood glucose sensing

摘要

A simple and general procedure is designed for in situ growth of gold nanoparticles (AuNPs) on hydrogen-bond supramolecular structures. The resulting nanocomposites are obtained via a one-pot synthetic method using chloroauric acid (HAuCl_4), sodium citrate, melamine (M) and cyanuric acid (CA) as pre cursors. At room temperature, melamine cyanurate (MCA) is formed immediately by M and CA through hydrogen bond self-assembly, possesses rich nitrogen content (49.4 wt%), and provides evenly dispersed and active sites to anchor and stabilize gold nanoparticles (AuNPs) as an ideal scaffold. The nanocompos ites (AuNPs/MCA) exhibit high peroxidase-like activity that can catalyze the oxidation-reduction reaction of H_2O_2 and peroxidase substrates over a broad pH range, including nearly neutral conditions (pH 5.0-7.4), as well as excellent stability. Combined with glucose oxidase (GOx), AuNPs/MCA are successfully used for the quantitative determination of blood glucose via one-pot colorimetric assay. This study develops an economic approach for preparation of peroxidase mimetics with high catalytic activity at neutral pH, and well stability, expected to provide guidelines for other types of inorganic/supramolecule nanocomposites, and to broaden their applications in analytical chemistry and environmental science.