Synthesis Of Oxide Nanostructures Modified Metal Wire And Their Applications In Biosensors

A biosensor is an analytical device,used for the detection of a chemical substance,that combines a biological component with a physicochemical detector.There are many potential applications of biosensors in the fields of food application,clinical monitoring,and environmental detection.Biosensors have always been a research hotspot in recent years.Metal oxide has been widely used in biosensors for its excellent performance and good catalytic activity.In this thesis,metal oxides or composite metal oxides nanostructures were grown on the metal wires by hydrothermal method.Morphology,phase and composition were characterized by SEM,XRD and TEM.The electrochemical performance was also studied by electrochemical analyzer.The specific research content is shown as follows:?1?Synthesis of NiO nanosheets modified nickel wire for detecting uric acidNiO nanoflakes modified Ni wire was synthesized by hydrothermal method.The composition and morphology of the product were characterized by SEM,TEM,and EDS.The results revealed that NiO nanoflakes were polycrystalline with a thickness of about 15nm.The modified nickel wire can be used as an excellent electrode in uric acid sensor.It exhibited good electro-catalytic performance with a high sensitivity of 813.8?A?mmol^-1cm^-2,a wide linear range of 1-900?mol/L,and a low detection limit of 0.1?mol/L.The NiO nanoflakes modified Ni wire electrode prepared here also has a good selectivity to UA.?2?Synthesis of Ni₆MnO₈ nanosheets modified needle for detecting ascorbic acidThis work describes the use of a steel acupuncture needle as the electrode substrate for construction of a Ni₆MnO₈ nanoflakes layer modified microneedle sensor for highly sensitive ascorbic acid detection.To construct the functionalized acupuncture needle,the needle surface was first coated with a carbon film as a seed layer.Subsequently,a simple hydrothermal reaction and calcination process was employed to growth of Ni₆MnO₈ nanoflakes on the needle as a sensing interface.Electrochemical study demonstrated that the Ni₆MnO₈ nanoflakes modified acupuncture needle electrode exhibited excellent performance toward the amperometric detection of ascorbic acid.It exhibited a high sensitivity of 3106?A?mM-1cm-2,a detection limit of 0.1?M,and a wide linear range from 1?M to 1.9 mM.The results demonstrate that the Ni₆MnO₈nanoflakes modified acupuncture needle is a promising new platform for the construction of non-enzymatic ascorbic acid sensors.?3?Synthesis of Co-Ni composite oxide nanoflakes for detecting ascorbic acidCo-Ni composite oxide nanoflakes were synthesized on the fine tungsten wire by hydrothermal method.The composition and morphology of the nanoflakes were characterized by SEM,TEM,and XRD.The results revealed that Co-Ni composite oxide nanoflakes were polycrystalline with a thickness of about 17 nm.The modified tungsten wire can be used as an excellent non-enzymatic electrode in ascorbic acid sensor.It exhibited good electro-catalytic performance with a high sensitivity of 6073?A?mmol^-1cm^-2,a wide linear range of 1-2100?mol/L,and a low detection limit of 0.5?mol/L.