Construction Of CuO-based Electrochemical Sensing Nano-Interface Using Carbonaceous Spheres As Template/Carrier

Electrochemical sensors have been developed for decades,and the construction of electrochemical sensors with high-performance nano-sensitive interfaces has always been the focus of analytical chemistry.How to make full use of the active sites of nanomaterials and effectively improve the sensitivity of the analyte is one of the research hotspots of electrochemical sensors at present.In recent years,porous and highly dispersed nanomaterials have attracted much attention because of their large active surface area and high active site utilization.Preparation of porous and highly dispersed semiconductor oxide nanomaterials and construction of electrochemical nano-sensitive interface are of great significance to improve the detection performance of electrochemical sensors.In this paper,carbonaceous spheres with high conductivity and good controllability were used as templates/carriers to construct the composite materials of three-dimensional porous CuO film nano-sensitive interface and carbonaceous spheres loaded with Cu/Cu₂₊₁O nanoparticles.They were applied to the electrochemical research of hydrazine and glucose,and achieved high sensitivity,high stability,high repeatability and low detection limit,and showed good practical application value.The main research work is as follows:1.Electrochemical study on the application of sensitive nano-interface of three-dimensional porous CuO thin film to hydrazine:Carbonaceous spheres with good dispersion and uniform particle size were synthesized by hydrothermal method.And uniform and compact carbonaceous spheres were prepared on tin indium oxide conductive glass（ITO）by Langmuir-Blodgett self-assembly technology.Three-dimensional porous CuO thin film was successfully constructed by drop-coating method and in-situ thermal oxidation method.Compared with CuO thin film,CuO thin film with three-dimensional porous structure had a larger active area,which was beneficial to the diffusion of molecules to be measured.The electrochemical results showed that the three-dimensional porous CuO thin film electrode had a good electrochemical response to hydrazine,with a sensitivity as high as 2497μA m M^-1cm^-2 and a detection limit as low as 0.04μM.High sensitivity and low detection limit fully reflect the role of three-dimensional porous thin film nanomaterials in improving electrochemical detection performance.2 The electrochemical detection of glucose by Cu/Cu₂₊₁O nanoparticles loaded on carbonaceous spheres:The carbonaceous spheres were prepared by hydrothermal method,and the sensitive materials loaded with Cu/Cu₂₊₁O nanoparticles were obtained by copper ion adsorption and in-situ thermal reduction in nitrogen atmosphere.The effects of copper ion adsorption capacity and in-situ thermal reduction temperature in nitrogen atmosphere on the morphology and composition of the sensitive material were studied in detail.The electrochemical results showed that Cu/Cu₂₊₁O nanoparticles supported on carbonaceous spheres obtained by adsorption capacity of 0.20 mmol copper ions and in-situ thermal reduction temperature of 400°C showed excellent electrochemical performance for glucose.The sensitivity was as high as 64.8μA m M^-1 cm^-2,the detection limit was as low as 62 n M（S/N=3）,and it still had obvious current response to 0.3μM glucose.The nanometer sensitive material had a wide linear range of 0.3μM-24.5 m M,had good selectivity for glucose,and had almost no obvious response to other interferents in serum.In addition,it showed strong stability,and the attenuation rate was only 11.95%after being tested for 120 min in alkaline environment.The recovery rate was as high as 110.2%by analyzing the actual serum samples.