The Preparation And Catalytic Activity Study Of Perylene Diimides Functionalized Metal Oxide Nanocomposites

Natural enzymes,existing in some plants,are widely used in biosensors and other detection methods because of their high specificity and high efficiency under the mild conditions.However,many intrinsic shortcomings of natural enzymes,such as easy denaturation,complicated and time-consuming preparation together with purification,limited their further application.With the development of nanoscience and nanotechnology,nanomaterials as peroxidase mimics were prepared successfully,overcoming the disadvantages of natural enzymes described above.Nevertheless,single nanomaterials show relatively low catalytic activity for its own properties.Therefore,people focused on improving the catalytic performance of single materials through functionalizing.In this work,perylene diimides(PDI)with carboxyl was firstly used to combine with cobalt oxide(Co3O4)and copper oxide(CuO)to obtain organic-inorganic nanocomposites(PDI-Co3O4 and PDI-CuO)by a facile hydrothermal method.These nanocomposites were characterized by TEM,XRD,and FT-IR,etc.According to the experimental results,the as-prepared organic-inorganic nanocomposites were confirmed to possess higher peroxidase-like activity than that of pure Co3O4 and CuO without PDI,and could accelerate the catalytic oxidation reaction of the colorless chromogenic substrate TMB in the presence of H2O2 into a blue product(ox TMB)observed by the naked eye.Otherwise,the fluorescent probe was utilized to investigate the catalytic mechanism of PDI-Co3O4 and PDI-CuO.Based on the experimental results,two distinct mechanisms could be obtained.The catalytic mechanism of PDI-Co3O4 come from the electron transfer while that of PDI-CuO was due to hydroxyl radical from the decomposition of H2O2.Based on the excellent catalytic activity of the as-prepared nanocomposites,the convenient colorimetric systems were developed to detect H2O2 and glucose,respectively.For H2O2 detection,PDI-Co3O4 system had a limit detection of 2.37 μM with a linear range from 3 to 60μM,and PDI-CuO had a limit deteciton of 2.38μM with the linear range was 5-100 μM.Besides,for glucose detection,the limit of detection for PDI-Co3O4 and PDI-CuO were 2.77 μM and 0.65 μM,and the linear range were 3-30 μM and 5-50 μM,respectively.It was verified that our constructed colorimetric sensors exhibited a higher sensitivity and better linear response.