High-performance peroxidase mimics for rapid colorimetric detection of HO and glucose derived from perylene diimides functionalized CoO 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 CoO nanoparticles through a facile two-step hydrothermal method and obtain the PDI functionalized CoO nanocomposites (PDI-CoO NCs). PDI-CoO 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-CoO NCs possessed the higher peroxidase-like activity than that of CoO nanoparticles without PDI, and could rapidly catalyze oxidation reaction of the chromogenic substrate TMB in the presence of HO to a blue product (oxTMB) observed by the naked eye. The improved catalytic activity of PDI-CoO NCs for colorimetric reactions could be attributed to the synergistic effects of PDI and CoO nanoparticles. On the basis of these experimental results, a convenient colorimetric system based on PDI-CoO as enzyme mimic that is highly sensitive and selective was developed for glucose detection. Meanwhile, the electron transfer between HO 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.