Electrochemical biosensor is a technology that converts chemical signals generated by reaction with specific biometric units into electrical signals.It has the advantages of high sensitivity,fast response speed,low cost,small and portable,etc.and play an important role in clinical medicine,environmental detection,inspection and quarantine.

　　The highly catalytically active metal oxide recognition unit is one of the important development directions of electrochemical biosensor technology.However,the metal oxide identification unit has low conductivity,which seriously hinders the electron transfer process during the reaction,and the sensing performance is not good.

　　Therefore,from the perspective of designing high-efficiency electrochemical biosensor electrode structure,it is the focus and difficulty of research in this field to construct a highly conductive nano-film structure conversion unit to load high catalytic activity recognition unit.

　　Film Materials and Interface Research Group Zhai Chaofeng made the study under the guidance of Jiang Xin Researcher and Huang Nan Associate Researcher,from Shenyang Materials Science National Research Center Joint Research Department.A novel diamond/carbon nanowall-loaded CuO three-dimensional network electrochemical sensing electrode was developed by CVD,PVD and electrochemical oxidation techniques and used for the detection of glucose molecules.

　　The electrochemical sensing electrode exhibits wide linear detection range(0.5×106-4×103 M),high sensitivity(1650μA cm-2 mM-1),low detection limit,good selectivity,excellent reproducibility and long-term stability.Further study found that the electrode presented a good recovery rate(94.21-104.18%)in the actual analysis of human serum,and had a high biomolecular recognition ability.

　　The analysis shows that the excellent electrochemical sensing performance mainly comes from the diamond/carbon nanowall thin film electrode with excellent physical and chemical properties.On the one hand,carbon nanowalls are composed of dozens of graphene sheets grown almost perpendicular to the substrate,which not only have excellent electrical conductivity and large specific surface area,but also have rich features of high electrochemical activity of graphite edges,open pore structure with easy mass transfer,difficulty in agglomeration and structural stability.On the other hand,high Young's modulus diamond penetrates the entire thin film electrode in the form of nanosheets,further improving the mechanical structural stability of the electrode during application.This unique three-dimensional network structure accelerates the mass transfer of glucose molecules and timely transports electrons generated by the catalytic reaction back to the electrochemical loop,thereby demonstrating excellent electroanalytical performance and long-term stability.

　　In addition,the three-dimensional network electrochemical sensing electrode is also suitable for loading other biometric units,and exhibits great potential in the field of high performance electrochemical biosensors.The carbon nanostructure will also have research value in the fields of electrochemical energy storage and conversion,electrocatalysis and so on.

　　Diamond,as one of the most special materials in natural world,is featured with the highest hardness,low friction coefficient,high elasticity modulus,high thermal conductivity,high insulation class,wide energy gap,great sound propagation rate and favorable chemical stability,which are presented in below Table.In spite of such unique features,the natural diamond has always been existed in the form of gem,with its variability and rareness sharply limiting its application.Luoyang Yuxin Diamond Co.,Ltd‘s CVD Diamond film,on the other hand,integrates such physical and chemical properties,with lower cost than natural diamond and applicable to be made into various shapes,thus enjoying extensive application prospect in electronic industry,optical field and mechanical industry.