Hierarchical Metal Oxide/Hydroxide Nanostructure And Their Applications To The Detection Of Non-enzymatic Sensor

With the continuous improvement of people’s living standards,the prevalence of diabetes in our country has been gradually increased,which has become the important chronic non-communicable disease that is seriously harmful to people’s health after cardiovascular disease and cancer.Therefore,developing efficient methods of blood glucose testing has a significant effect on the rapid diagnose,the prevention and treatment in time of diabetes.The glucose sensor is a type of device which is capable of detecting the concentration of the glucose,having been experienced the development of enzyme senor and non-enzymatic sensor.Because of the poor stability and expensive price of the enzyme,which makes more and more researchers began to develop the non-enzymatic electrochemical glucose sensor.Among the non-enzymatic sensors,the materials based on the alloy,and metal oxide/metal hydroxide are used to detect the glucose,and its working principle mainly depends on the inherent electronic structure and the surface diffusion reaction of the electrode materials.The hierarchical structure owns special physicochemical properties,such as specific surface area,multiple channels,difficult to aggregate,which is due to its novel structure;in addition,concerning about the huge influence to the properties based on the morphology and the size,it will make the hierarchical structure have more novel applications,especially in the manufacture of sensor devices,which will have more potential applications,and it has been widely focused in recent years.In this paper,the hierarchical structured inorganic nanomaterials were fabricated via chemical synthesis method,showing good morphologies and excellent electrochemical properties,which is applied in medical test,food industry,environmental monitoring,and biotechnology.Additionally,the electrochemical properties based on the structure and the material were investigated,which offered a novel thought on the synthesis of other hierarchical nanomaterials.The main research was as follows:(1)The flower-like hierarchical Cu2O was synthesized via microwave-assisted hydrothermal synthesis method,and its morphology,crystallinity,and surface properties were characterized by scanning electron microscope(SEM),and X-ray diffraction(XRD).According to the electrochemical method,the obtained glucose sensor was detected,with a linear range from 9.99×10’6 M to 1.77×10-4 M.Under low concentrations,its sensitivity is as high as 301.99μA ·mmol-1 cm 2,with a detection limit of 2.13×10-7M.In addition,it has a good interference on urea,creatinine,ascorbic acid and hydrogen peroxide,showing that it has excellent selectivity.(2)Ni(OH)2 hollow spheres were fast fabricated via a chemical etching process based on highly uniform dispersed Cu2O spheres used as hard template,which were synthesized through a facile chemical method at room temperature.The non-enzymatic electrochemical sensor was simply made by dropping the material to the surface of the glass carbon electrode(GCE),which was applied to the direct detection of glucose.The cyclic voltammetry showed that the obtained samples revealed excellent electrocatalytic activity.The non-enzymatic electrochemical sensor was used in the detection of glucose with a detection limit of 9.98×10-7 M(S/N = 3),a wide linear detection ranged up to 9.99×10-6 M～4.60×10-4 M,a high sensitivity of 1122.96μA·mM-1·cmO2 and good selectivity toward glucose.(3)The hierarchical NiO hollow spheres were synthesized based on carbon microspheres.The morphology,surface property and crystallinity were characterized by SEM,and XRD.The detection limit of the sensors to the glucose was 0.998 μM(S/N = 3)at a potential of 0.57 V,with a correlation coefficient of 0.9947,a linear range from 9.99 μM to 0.177 mM,a sensitivity of 609.12 μA·mmol-1·cm-2.Additionally,it revealed an excellent selectivity on urea,ascorbic acid,creatinine,and hydrogen peroxide.(4)Nanostructured Indium hydroxide(In(OH)3)was synthesized through a facile hydrothermal route without any polymer surfactants.The experiment results revealed that the obtained material exhibited good electrocatalytic activity for the detection of UA in sodium hydroxide solution.In addition,compared with In2O3,In(OH)3 showed higher electrode stability.The non-enzymatic electrochemical sensor was used in the detection of UA with a detection limit of 75 nM(S/N = 3),a wide linear detection ranged up to 4.696×10-4 M,a high sensitivity of 301.3 μA·mM-1·cm-2 and good selectivity toward UA.