Preparation Of Electrochemical Biosensor Based On Graphene And The Study Of Characterization

Electrochemical biosensor is the development product of electrochemical technology and biosensor,and it is one of the most active fields in current analytical research.Electrochemical biosensor has the advantages of high sensitivity,good selectivity and fast response,which can be widely used in medical field,environmental monitoring,food,agriculture and other fields.Gold nanoparticles are a new kind of functional nanomaterials,they have high specific surface area,conductivity and catalytic activity,which has aroused the interest of research workers extensively.Graphene is a two-dimensional material with huge surface area,ultra-high electron mobility,which is an excellent electrode material for electrochemical sensor fabrication.In this paper,a kind of composite material is prepared by using graphene as the skeleton carrying gold nanoparticles.Then the functional material is used to load the biomolecules,construct the electrochemical biosensor,and test the performance of the sensor.The specific research work is as follows:.(1)This paper uses the improved Hummers method to prepare the redox graphene(GO).Because GO and Nafion have the same electrical power,they are dispersed and the redox graphene is reduced by electrochemical method.A series of characterization methods were used to characterize the graphene and the graphene oxide.(2)The composite functional materials of graphene and gold nanoparticles were successfully prepared by electrodeposition,and the direct electron transfer at the modified electrode interface was realized.By means of FTIR,SEM,AFM and Raman,the results show that the composite functional materials of graphene oxide and gold nanoparticles have the properties of graphene and gold nanoparticles.And graphene and graphene have synergistic effect,promote each other,and successfully make the graphene functional.Using Ampere method to detect hydrogen peroxide(H2O2)fromt 1Oμm to 14mM,the lower limit was 2.5μm(noise ratio S/N=3),and the electrochemical biosensor had good stability and reproducibility.(3)The composite materials of grapheme(ERGO)and gold nanoparticles(AuNPs)prepared by electrodeposition were used as electrode materials,then the cytochrome c was loaded and construct a new biosensor for hydrogen peroxide.The electrochemical activity of cytochrome c at the electrode surface was studied in detail by electrochemical test.The experiment shows that the composite functional material of graphene and Skinner can load more cytochrome c because of its larger surface area.The composite has good biocompatibility,so that the loaded cytochrome c can maintain its biological activity.And because gold nanoparticles can be used as "wires" to link the center body of heme potential with the surface of the electrode,it can better promote the interfacial electron transfer of the modified electrode and the catalytic activity of cytochrome c.In addition,the GCE/ERGO-Nafion/AuNPs/Cyt c/nafion sensor has good detection effect on H2O2 and has stability and reproducibility.