Metal-organic framework (MOF) hybridized gold nanoparticles as a bifunctional nanozyme for glucose sensing

Inspired by natural enzymes that possess multiple catalytic activities, here we develop a bifunctional metal-organic frame-work (MOF) for biosensing applications. Ultrasmall gold nano-particles (AuNPs) are grown in the internal cavities of an iron (Fe) porphyrin-based MOF to produce a hybridized nanozyme, AuNPs@PCN-224(Fe), in which AuNPs and PCN-224(Fe) exhibit the catalytic activity of glucose oxidase (GOx) and horseradish peroxidase (HRP), respectively. We established that the bifunctional nanozyme was capable of a cascade reaction to generate hydrogen peroxide in the presence of d-glucose and oxygen in situ, and subsequently activate a colorimetric or chemiluminescent substrate through HRP-mimicking catalytic activity. The nanozyme was selective over a range of other saccharides, and 93% of the catalytic activity was retained after being recycled five times.

Automated summary

Inspired by natural enzymes, a bifunctional metal-organic framework (MOF), AuNPs@PCN-224(Fe), was developed for biosensing applications. The hybridized nanozyme, consisting of ultrasmall gold nanoparticles (AuNPs) and iron porphyrin-based MOF (PCN-224(Fe)), exhibited the catalytic activities of glucose oxidase (GOx) and horseradish peroxidase (HRP). The bifunctional nanozyme enabled a cascade reaction to generate hydrogen peroxide and activate a colorimetric or chemiluminescent substrate. Selectivity over other saccharides and high catalytic activity retention were observed.