Solution-Phase Synthesis of Platinum Nanoparticle-Decorated Metal-Organic Framework Hybrid Nanomaterials as Biomimetic Nanoenzymes for Biosensing Applications

The synthesis of nanomaterials with specific properties and functions as biomimetic nanoenzymes has attracted extensive attention in the past decades due to their great potential to substitute natural enzymes. Herein, a facile and simple method for the preparation of platinum nanoparticle (PtNP)-decorated two-dimensional metal-organic framework (MOF) nanocomposites was developed. A ligand with heme-like structure, Fe(III) tetra(4-carboxyphenyl)porphine chloride (TCPP(Fe)), was applied to synthesize MOF nanosheets (denoted as Cu-TCPP(Fe) nanosheets) in high yield. Ultrathin Cu-TCPP(Fe) nanosheets with thickness less than 10 nm were used as a novel template for the growth of ultrasmall and uniform PtNPs. Significantly, the obtained hybrid nanomaterials (PtNPs/Cu-TCPP(Fe) hybrid nanosheets) exhibit enhanced peroxidase-like activity compared to PtNPs, Cu-TCPP(Fe) nanosheets, and the physical mixture of both due to the synergistic effect. On account of the excellent peroxidase-like activity of PtNPs/Cu-TCPP(Fe) hybrid nanosheets, we established a colorimetric method for sensitive and rapid detection of hydrogen peroxide. Furthermore, by combining with glucose oxidase, a cascade colorimetric method was established to further detect glucose with excellent sensitivity and selectivity.