A Label-Free Colorimetric Assay Based on Gold Nanoparticles for the Detection of H2O2 and Glucose

The significance of sensing hydrogen peroxide (H2O2) is due to its ubiquity, being a potential biomarker as well as an end-product of several oxidation reactions. Herein, based on gold nanoparticles (AuNPs) and coupled with single-stranded DNA (ssDNA) and ceria nanoparticles (CeO2), we developed a novel colorimetric method to detect H2O2 and glucose in NaCl solutions. In the presence of H2O2, ssDNA adsorbed on the surface of CeO2 could be released and subsequently decorated AuNPs, resulting in a distinct color change of the aqueous solution from purple to red, which could be observed by the naked eye. Since H2O2 can be produced in the process of glucose oxidation by glucose oxidase (GOx), this approach can also be employed to detect glucose. By employing this sensing system, the detection limits for H2O2 and glucose are about 0.21 mu M and 3.01 mu M, respectively. Additionally, monitoring the content of glucose in blood serum samples was successfully achieved by the proposed strategy. This work opens a potential avenue for the quantitative detection of H2O2 and glucose in clinical diagnostics.

Automated summary

This study developed a novel colorimetric method for detecting hydrogen peroxide (H2O2) and glucose in sodium chloride solutions, based on gold nanoparticles, single-stranded DNA, and ceria nanoparticles. The method can detect the target substances by observing the color change of the aqueous solution, providing a potential avenue for quantitative detection in clinical diagnostics.