Silver nanoparticles@metal-organic framework as peroxidase mimics for colorimetric determination of hydrogen peroxide and blood glucose

Abstract

• A colorimetric strategy for sensitive detection of H 2 O 2 and glucose has been developed. • A broad dynamic response range for glucose in the range from 0.5 to 50 μM with a limit of detection of 0.23 μM. • The proposed method can be used to monitor glucose in human serum samples. As a major origin of energy for cellular activity and intermediates product of metabolism, glucose plays a significant role in biological activity. Thus, it is relatively vital to explore a sensitive and accurate approach to monitor blood glucose. Herein, a colorimetric biosensor for sensitive, rapid, and reliable monitoring of blood glucose was successfully established. In this sensing system, a nanocomposite of silver nanoparticles (AgNPs) depositing on the MIL-101 (Fe) surface (AgNPs@MOF) was employed as an excellent peroxidase mimic. Glucose could be effectively catalyzed by glucose oxidase (GOx) to produce hydrogen peroxide (H 2 O 2 ) and gluconic acid. Afterward, the AgNPs@MOF nanozyme catalyzed the oxidation of the colorless material TMB into the blue product oxTMB by H 2 O 2 , causing a noticeable change in absorbance at 652 nm. A colorimetric glucose measurement platform was proposed with preferable simplicity and high sensitivity using GOx and AgNPs@MOF nanozyme that with peroxidase-mimicking activity. The limit of detection of the established biosensor was down to 0.17 μM for H 2 O 2 and 0.23 μM for glucose. More importantly, as a result of the application of this biosensor with human blood samples, glucose levels could be monitored with high accuracy, which indicated that this approach had great potential for diabetes therapy. A colorimetric biosensor for sensitive, rapid, and reliable monitoring of blood glucose was successfully established. In this sensing system, a nanocomposite of silver nanoparticles (AgNPs) depositing on the MIL-101 (Fe) surface (AgNPs@MOF) was employed as an excellent peroxidase mimic. Glucose could be effectively catalyzed by glucose oxidase (GOx) to produce hydrogen peroxide (H 2 O 2 ) and gluconic acid. Afterward, the AgNPs@MOF nanozyme catalyzed the oxidation of the colorless material TMB into the blue product oxTMB by H 2 O 2 , causing a noticeable change in absorbance at 652 nm.