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

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.