New progress has been made in the research of diamond film materials
Electrochemical biosensor is a technology that converts chemical signals generated by reactions with specific biometrics units into electrical signals. It has the advantages of high sensitivity, fast response speed, low cost and small portability, and plays an important role in clinical medicine, environmental detection, inspection and quarantine. Metal oxide recognition unit with high catalytic activity is one of the important development directions of electrochemical biosensors. However, the low conductivity of metal oxide recognition unit seriously hinders the electron transfer process in the reaction process, and the sensor performance is not good. Therefore, from the perspective of designing the structure of high-efficiency electrochemical biosensor electrode, it has become the focus and difficulty of this field to construct the conversion unit of nanometer thin film structure with high conductivity to load the identification unit of high catalytic activity.
Metal by shenyang national research center of materials science research, membrane materials and interface team Jiang Xin researcher, Dr. Graduate ZhaiChaoFeng Huang Nan associate professor instruction, using CVD, PVD and electrochemical oxidation technology to develop a new type of diamond/carbon nanotubes wall load CuO 3 d mesh electrochemical sensing electrode and used in the detection of glucose molecules. The electrochemical sensing electrode showed wide linear detection range (0.5 x 106-4 x 103 M), high sensitivity (1650 A 1 cm - 2 mM), low detection limit and good selectivity, good reproducibility and long-term stability, and further studies have found that the electrode in the practical analysis of human serum showing A good recovery rate (94.21 104.18%), has the very high biological molecular recognition ability.
The results show that the excellent electrochemical sensing performance mainly comes from diamond/carbon nanowall thin film electrodes with excellent physical and chemical properties. On the one hand, carbon nanowires are composed of dozens of graphene sheets that grow almost perpendicular to the substrate. They not only have excellent electrical conductivity and large specific surface area, but also have rich graphite edges with high electrochemical activity, porous structure that is easy to transfer mass, difficult to agglomerate and stable structure. On the other hand, diamond with high young's modulus runs through the whole thin film electrode in the form of nano-sheet, which further improves the mechanical structure stability of the electrode in the application process. This unique three-dimensional network structure can speed up the mass transfer of glucose molecules, and return the electrons generated by catalytic reactions to the electrochemical circuit in time, thus showing excellent electrical analysis performance and long-term stability. In addition, the 3d mesh electrochemical sensor electrode can also be used to load other biometrics, showing 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 transformation, electrocatalysis and so on. Related research results to published in Small (in press, https://doi.org/10.1002/smll.201901527).
The above basic research work has been funded by the national natural science foundation of China, the science and technology foundation of liaoning province and the major scientific and technological achievements transformation project of shenyang.
Fig.1 schematic diagram of electrochemical sensor electrode structure and biosensor detection of CuO nanoparticles loaded on 3d diamond/carbon nanowall
FIG. 2 electrode sensitivity, anti-interference, selectivity and long-term stability of CuO electrochemical sensor loaded with 3d diamond/carbon nanowall