Preparation Of Nitrogen Doped The Reduced Graphene Oxide/Multi-morphology Cu₂O As Electrode Materials And Its Electrochemical Detection Of Glucose

Diabetes,a chronic disease causing metabolic and systemic disorder by elevated levels of glucose,occurs due to malfunctioning of pancreatic responsible for production of insulin which glucose level in the blood.Long-term high levels of glucose can cause the lesion of tissues and organs,leading to occurrence of complications.About 422 million people worldwide died of diabetes.Control the levels of blood glucose can effectively reduce the incidence of diabetes and its complications in clinical studies.Therefore,blood glucose level is the reference value in the diagnosis and treatment of diabetes.Electrochemical glucose sensor has been widely attention for its accurate,high sensitivity and low cost devices for detection.The application of nanomaterials can provide new materials to improve the performance of electrochemical glucose sensor.Nano-cuprous oxide is a p-type semiconductor which has a 2.17eV direct band gap,it has a wide range of applications in the photoelectric catalytic,biosensors,solar photoelectric conversion and other fields.The macroscopic physical and chemical properties of cuprous oxide are determined by the size and morphology of the particles.The changing experimental conditions can affect the growth rate of crystal,and then synthesize cuprous oxide nanoparticles with different morphologies.Graphene,has a large specific area and great conductivity,can accelerate the transfer rate between the electrons as the ideal carbon carrier material.The doping graphene material which the foreign atoms(N,B,S,etc)is leaded into the graphene skeleton can enhance the electrochemical behavior of the active sites on its surface.The composite material which doping graphene and metal oxide form as the modified electrode can further improve the electrocatalytic activity of glucose sensor.In this paper,the nitrogen doped reduced graphene was synthesized under high temperature and the nitrogen as the nitrogen source.The octahedral cuprous oxide,cubic cuprous oxide and hollow spherical cuprous oxide were loaded into the surface of N-doped reduced graphene to form multi-morphology Cu2O/N-rGO nanocomposites materials by chemical precipitation method.The nanocomposition,morphplogy and structure of the multi-morphology Cu2O/N-rGO composites were characterized by XRD,SEM,FT-IR,XPS.Non-enzymatic glucose sensors were constructed with the composites and their electrocatalytic properties were investigated.The main research contents and conclusions are follows:(1)The preparation of N-rGO.The graphite oxide was prepared from the natural graphite powder by modified Hummers method,and then the graphene oxide was obtained by ultrasonic stripping.The mixture which are made up of ammonia and graphene oxide was heat treated at a high temperature under the protection of N2.The oxygen-containing functional groups on the surface of GO break down and break away to form the active center,the high temperature could make GO become the graphene(rGO)and the nitrogen also was doped into rGO.to obtain the nitrogen doped reduced graphene(N-rGO)under the process.(2)The best experimental scheme for the synthesis of multi-morphology cuprous oxide.Three different reducing agents(hydrazine hydrate,ascorbic acid and hydroxylamine hydrochloride)were used to synthesize multi-morphology of cuprous oxide by chemical precipitation method.The growth rate of crystal was affected by changing the concentration of NaOH without surfactant to obtain the multi-morphology cuprous oxide.The optimum reducing agent and experimental scheme were determined by XRD and SEM.The hydrazine hydrate as the reducing agent to synthesis the multi-morphology cuprous oxide(octahedral,cube and hollow spherical).(3)The electrochemical test of multi-morphology Cu2O/N-rGO nanocomposites.The multi-morphology Cu2O/N-rGO nanocomposite was prepared by chemical precipitation method,and it was used as the electrode modified materials of glucose sensor.The catalytic activity of the modified electrodes are tested by using the cyclic voltammetry,electrochemical impedance spectroscopy and chronoamperometry.The results show that the nanocomposite has great electrical conductivity and significant catalytic activity for glucose.The hollow sphere Cu2O/N-rGO modified electrode has the highest catalytic activity for glucose,and its detection range is 12.5?M-1.2mM,the sensitivity is 4524.8?A/(mM cm2),the lowest detection limit is 2.18?M.In addition,the modified electrodes exhibit good selectivity and anti-interference.