High-performance peroxidase mimics for rapid colorimetric detection of H2O2 and glucose derived from perylene diimides functionalized Co3O4 nanoparticles.

N,N'-di-caboxy methyl perylene diimides (PDI), as one of the most promising functional materials in optional chemosensing, was first used to combine with Co3O4 nanoparticles through a facile two-step hydrothermal method and obtain the PDI functionalized Co3O4 nanocomposites (PDI-Co3O4 NCs). PDI-Co3O4 NCs were characterized by a series of technical analysis including transmission electron microscope (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), respectively. The experimental results indicated that the as-prepared PDI-Co3O4 NCs possessed the higher peroxidase-like activity than that of Co3O4 nanoparticles without PDI, and could rapidly catalyze oxidation reaction of the chromogenic substrate TMB in the presence of H2O2 to a blue product (oxTMB) observed by the naked eye. The improved catalytic activity of PDI-Co3O4 NCs for colorimetric reactions could be attributed to the synergistic effects of PDI and Co3O4 nanoparticles. On the basis of these experimental results, a convenient colorimetric system based on PDI-Co3O4 as enzyme mimic that is highly sensitive and selective was developed for glucose detection. Meanwhile, the electron transfer between H2O2 and TMB was responsible for the oxidation of TMB. The present work demonstrates a general strategy for the design of organic molecules functionalized oxide for different applications, such as nanocatalysts, biosensors and nanomedicine.