Preparation And Properties Of Electrochemical Sensor Based On Functional Graphene/Nickel Foam

Electrochemical sensors are widely used in medical inspection,industrial production,environmental monitoring and many other fields due to their advantages of low cost,simple operation and fast response.With the advancement of technology,people have put forward more stringent requirements on the performance of electrochemical sensors such as sensitivity,selectivity and stability.Traditional electrochemical sensors based on precious metals and enzymes have been unable to meet the requirements for efficient detection of analytes in various fields,which owing to their poor stability,low sensitivity,and short life.Generally,using suitable nanomaterials to functionalize the surface of the sensing electrode is a good way to improve the detection performance of the sensor,and therefore,the development of a novel non-enzymatic and non-noble metal electrochemical sensing electrode based on nanomaterial modification has become popular.In this paper,we design two types of enzyme-free electrochemical sensor in order to detect dopamine and glucose biomolecules.The main research contents of this paper are as follows:a)The G/Ni composite was firstly fabricated by usingthree-dimensional nickel foam as the substrate via chemical vapor deposition method.Afterwards,the ordered mesoporous carbon/graphene/nickel foam（OMC/G/Ni）composite were successfully prepared by hydrothermal method by using phenolic resin as carbon source and triblock polymer F127 as soft template.Then the OMC/G/Ni composite was used as the enzyme-freedopamine sensing electrode to explore its detection properties fordopamine biomolecules.The results show that the OMC/G/Nisensor has excellent properties for dopamine detection with highsensitivity(1.09μAμM^-1cm^-2),wide linear range（0.05-58.75μA）,and low detection limit（0.019μA）.At the same time,the sensorwith good stability can reserve good sensing ability even underbending condition.b)The cobalt oxychloride/graphene/nickel foam（Co₃O₄/G/Ni）composite was firstly prepared by using the G/Ni composite as asubstrate and Co（OH）₂ as a precursor via one step hydrothermalmethod.Then the Co₃O₄/G/Ni composite was used as theenzyme-free glucose sensing electrode to study its detectionproperties for glucose biomolecules.The results show that thesensitivity of the sensor is 100.67μAμM^-1cm^-2 in the range of0.01 to 1.36 mM of glucose,the linear detection range is0.01-7.86 mM and the response time is less than 4 s,whichsuggesting that the sensor has excellent detection performance forglucose.