Fabrication Of Nickel Foam/Metal Oxides Self-Supported Electrodes And The Performances As A Glucose Sensor

Glucose sensors have been widely used in blood glucose detection,food and pharmaceutical processing,biotechnology and other fields.Non-enzymatic glucose sensor has attracted much attention due to its excellent stability and low cost.In this work,transition metal oxide electrode materials were prepared on the nickel（Ni）foam substrates by chemical methods to form the self-supported electrodes,including four kinds of porous materials:copper oxide,four oxidation three cobalt,cobalt nickel oxide and nickel manganate.These self-supported electrodes were used as a non-enzymatic glucose sensor to evaluate its linear range of concentration,sensitivity,detection limit,response time,selectivity and stability.The oxalic acid was used as a precipitator,the copper ion precipitation reaction took place on the surface of Ni foam by controlling the reaction conditions.The CuO precursor was directly grown on the surface of Ni foam.The Ni/CuO self-supported electrode was prepared after a heat treatment.The average pore size of porous CuO is about 22.0 nm,and the specific surface area is 26.1 m²g^-1.The Ni/CuO self-supported electrode sensor exhibits high sensitivity(2.39m A m M^-1 cm^-2)in the linear range（0.8-5 m M）.This Ni/CuO self-supported electrode sensor exhibits a low limit of detection of 0.96μM.In the CV curves,the peak currents have a linear relationship with the square root of the scanning rates.This electrochemical catalytic reaction is a diffusion-controlled electrochemical redox process.This electrochemical catalytic reaction completes the charge transfer through the Cu（Ⅲ）/Cu（Ⅱ）redox couples.In the actual detection of fetal bovine serum samples,the recovery rate is about97.86％-104.50％,and the relative standard deviation is not more than 3.21%.The oxalic acid was used as a precipitator,the reaction conditions were controlled so that the cobalt ion precipitation reaction occurred on the surface of Ni foam.The Co₃O₄ precursor was directly grown on the surface.This Ni/Co₃O₄ self-supported electrode was prepared after a heat treatment.The average pore size of porous Co₃O₄ is about 7.8 nm,and the specific surface area is 49.1 m² g^-1.This Ni/Co₃O₄ self-supported electrode exhibits a high sensitivity(30.6 m A m M^-1 cm^-2)in the linear range（1.073-7.067 m M）.This Ni/Co₃O₄ self-supported electrode exhibits a low limit of detection of 0.005μM.The peak currents have a linear relationship with the scanning rates.This catalytic reaction process is an electrochemical reaction control process.The electrochemical catalytic reaction completes the charge transfer through the Co（Ⅳ）/Co（Ⅲ）redox couples.In the actual detection of fetal bovine serum samples,the recovery rate is about 97.80％-103.75％,and the relative standard deviation is not more than 3.01%.The oxalic acid was used as a precipitator,the reaction conditions were controlled so that the precipitation reaction of nickel ions and cobalt ions occurred on the surface of Ni foam.The NiCo₂O₄ precursor was directly grown on the surface.The Ni/NiCo₂O₄ self-supported electrode was prepared after a heat treatment.The average pore size of porous NiCo₂O₄ is about 12.4 nm,and the specific surface area is 33.4 m² g^-1.This Ni/NiCo₂O₄ self-supported electrode exhibits a high sensitivity(5.0 m A m M^-1 cm^-2)in a wide range（0.99-67.2μM）.This Ni/NiCo₂O₄ self-supported electrode exhibits a low limit of detection of 0.9μM.The peak currents have a linear relationship with the scanning rates.This catalytic reaction process is an electrochemical reaction control process.The electrochemical catalytic reaction completes the charge transfer through the bimetallic Ni（Ⅲ）/Ni（Ⅱ）and Co（Ⅲ）/Co（Ⅱ）redox couples.In the actual detection of fetal bovine serum samples,the recovery rate is about97.80％-103.75％,and the relative standard deviation is not greater than 3.01％.The urea was used as a homogeneous precipitator,the precipitation reaction of nickel ions and manganese ions occurred on the surface of Ni foam by controlling hydrothermal reaction conditions.NiMn₂O₄ precursor was directly grown on the surface.The Ni/NiMn₂O₄ self-supported electrode was prepared after a heat treatment.The average pore size of porous NiMn₂O₄ is about 9.6nm,and the specific surface area is 77.5 m² g^-1.This Ni/NiMn₂O₄ self-supported electrode for detecting glucose exhibits the high sensitivity of 12.2m A m M^-1 cm^-2 in a wide range of 0.99μM-67.20μM.In addition,This Ni/NiMn₂O₄ self-supported electrode also exhibits a low LOD of 0.24μM.The peak currents have a linear relationship with the square root of the scanning rates.This electrochemical catalytic reaction is a diffusion-controlled electrochemical redox process.This electrochemical catalytic reaction completes the charge transfer through the bimetallic Ni（Ⅲ）/Ni（Ⅱ）and Mn（Ⅳ）/Mn（Ⅲ）redox couples.In the actual detection of fetal bovine serum samples,the recovery rate is about 99.25％-103.50％,and the relative standard deviation is not greater than 2.03％.