The Synthesis Of Transition Metal Nanoarray Materials And The Research Of Non-enzymatic Electrochemical Sensing

Electrochemical sensors are widely regarded as the most potential applications in the field of environmental monitoring,clinical diagnosis,food safety and biopharmaceuticals,because of the advantages of good selectivity,high sensitivity,simple operation,low cost,fast analysis and easy to miniaturization.Transition metal nanomaterials have been widely used in electrochemical sensing research due to their advantages such as low cost,high storage abundance and environmental friendliness.In the process of electrochemical reaction,the element composition and surface state of electrode materials are very important for electrochemical sensing with high sensitivity and high stability.In this paper,we mainly studied the preparation and electrocatalytic properties of several transition metals derivative nanoarray materials,and applied them to the electrochemical detection of glucose,hydrogen peroxide.The research content mainly includes 3 parts,and the main contents can be concluded as follows:1.Iron nickel bimetallic nitride（Fe₂Ni₂N）nanosheet array for nonenzymatic glucose electrochemical sensingIn this study,a homogeneous iron nickel hydroxide nanosheet array was uniformly grown on titanium mesh（TM）substrate by a simple one-step hydrothermal method,and then iron nitride bimetallic nitride was obtained by nitridation from iron nickel hydroxide.The materials were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electronic microscope（TEM）and X-ray photoelectron spectroscopy（XPS）etc.The results showed that the Fe₂Ni₂N nanosheet array were uniformly vertically grown on TM.It is worth mentioning that the bimetallic nitride nanoarray material has high stability,electrical conductivity and large specific surface area,which is very important for the field of electrocatalysis.We used thus Ni-Fe bimetallic nitrides as glucose detection electrodes,traditional mode of three electrodes was used in this study,and the results of glucose detection show that this material has excellent electrocatalytic propertie.And the limit of detection（LOD）is 38 nM,detection range is 0.05μM-1.5 mM,the response time is less than 3 s,and this sensor has strong anti-interference abilit.At the same time,the results of glucose detection in real blood samples are satisfactory,which prove that the method has great potential for development in real samples detection.2.Nickel phosphide（Ni₂P）nanosheets nanoarry for nonenzymatic hydrogen peroxide detectionIn this study,titanium mesh（TM）was used as support substrate,and nickel hydroxide nanosheets array was uniform growth on TM by a sample hydrothermal method,and then,to obtain nickel phosphide,nickel hydroxide was treated by the low temperature phosphating.Such material was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electronic microscope（TEM）and X-ray photoelectron spectroscopy（XPS）etc.The results showed that the prepared Ni₂P nanosheets array were uniform distributed on TM.The 3D nickel phosphide electrode has shown good electrocatalytic properties of electrocatalysis water splitting,but this is the first time in the electrochemical detection of hydrogen peroxide.The electrochemical sensing of hydrogen peroxide was investigated by using the traditional three electrodes mode.Based on this,we established an analysis method for efficient hydrogen peroxide chemical detection.Under optimized conditions,the concentration of hydrogen peroxide has a good linear relationship with the current density in the wide range of 0.001 to 20 mM.The correlation coefficient R²is 0.9966,and the detection limit（LOD）is as low as 0.2μM,and the sensitivity is 690.7μA mM^-11 cm^-2.The results showed that the Ni₂P nanosheets array as the electrochemical sensing electrode of hydrogen peroxide has the advantages of low detection limit,good selectivity,short reaction time,which show that the transition metal phosphides nanoarray has great potential in the field of electrochemical sensing.3.Synthetise of shell-core structured Ni Cu-OH@Cu（OH）₂ nanowire array for nonenzymatic glucose detectionIn this study,copper foam（CF）was used as support substrate,shell-core structured NiCu-OH@Cu（OH）₂ nanowire array were grown on the surface of CF by the ways of chemical etching and ion exchange.Such material was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electronic microscope（TEM）and X-ray photoelectron spectroscopy（XPS）etc.The results show that NiCu-OH@Cu（OH）₂nanowire array uniformly distributed on the surface of CF.It is worth mentioning that the bimetallic nitride nanoarray material has high stability,electrical conductivity and large specific surface area,which is very important for the electrochemical activity enhancement.We used the shell-core structured materials as glucose detection electrode,traditional mode of three electrodes was used in this study,and the results towards glucose detection show that this material has a excellent electrocatalytic propertie.The limit of detection（LOD）is 32 nM,detection range is 0.1μM-1.5 mM,the response time is less than 3 s,and has high sensitivity,strong anti-interference ability and good stability.