Construction Of Color Sensing Based On The Preparation Of Copper Functional Nanomaterials

Optical sensor is based on the molecular recognition. Through the research on the molecules or assembly molecular for a special material identification process, and produce and transmit signals under the interaction of molecules, which could realize the specific material for testing of molecular devices. Color sensor as a kind of optical sensor, has many characteristics, such as the operation is simple, rapid, convenient, and can be widely used in biological analysis, environmental testing, food safety and medical diagnosis, etc. Enzyme is not easy to store, in addition, due to natural variability and the deactivation, so the synthesis of low cost, good catalytic performance of metal, nonmetal and composite nanomaterials as simulated enzyme instead of natural enzyme by a lot of people more and more attention. This experiment by ionic liquids as solvents coprecipitation method, composite functional materials, to assist the reduction method of the preparation of a series of humic acid catalytic performance good composite material, and the study found that these materials have excellent peroxidase activity and the unique optical properties. On this basis, combining the uv-vis absorption spectra, we built a series of color sensor. It is mainly divided into the following three aspects:?1? A nanomaterial of the chemical composition Cu₂?OH?₃Cl-CeO₂ and with a large surface area is shown to be a viable peroxidase mimetic. It was synthesized by co-precipitation of an aqueous solution containing Ce?III? chloride, Cu?II? chloride and hexamethylenetetramine by adding an ionic liquid. The material was characterized by scanning electron microscopy and X-ray powder diffractometry. The composite possesses peroxidase-like activity and catalyzes the oxidation of the peroxidase substrate 3, 3', 5, 5'-tetramethylbenzidine by H2O2 to produce a blue product. Based on this finding, a simple, rapid and selective colorimetric method was worked out for the determination of glucose and cholesterol by using the respective oxidases and by quantifying the H2O2 formed.?2? In this study, copper nanoparticles modified graphitic carbon nitride nanosheet?CuNPs/g-C3N4? as a novel peroxidase mimetic was successfully prepared by the calcination of dicyandiamide-Cu2+ complex with the assistance of humic acid. The morphology and structure of the product was characterized by X-ray powder diffractmeter?XRD?, Fourier transform infrared spectroscopy?FTIR? and transmission electron microscopy?TEM?. The prepared CuNPs/g-C3N4 was found to have highly peroxidase-like activity, which can rapidly catalyze the oxidation of peroxidase substance 3, 3', 5, 5'-tetramethylbenzidine?TMB? to produce a blue color reaction in the presence of H2O2. Accordingly, a simple, selective and fast colorimetric method was developed for H2O2 and glucose detection. The prepared CuNPs/g-C3N4 exhibited low detection limits with 3.2 × 10-8 M and 3.7 × 10-7 M for H2O2 and glucose, respectively.?3? In this report, stable copper nanoparticles?CuNPs? were prepared by a facile annealing process using humic acid as the reducing and stabilizing agent. The products were characterized by X-ray powder diffraction, scanning electron microscope and Fourier transform infrared spectroscopy. The prepared CuNPs show remarkable intrinsic peroxidase-like activity, which can fleetly catalyze the oxidation of peroxidase substrate 3, 3', 5, 5'-tetramethylbenzidine?TMB? in the presence of H2O2 to produce a blue color reaction. More importantly, the prepared CuNPs shows excellent stability, which can hardly been oxidized even after 6 months. Based on the above mechanism, a simple, rapid and selective colorimetric method for the glucose detection was developed, and the detection limit of the glucose was 6.86 × 10-7 M. This work provides a novel method for the preparation of stable CuNPs, which may have wide applications on the detection of glucose in human body and pear juice.