Fabrication And Properties Of CVD Graphene Sensor

Graphene is the first two-dimensional monoatomic layer material successfully prepared in the world.Its unique two-dimensional structure and excellent performance have aroused widespread concern in the scientific community in the past ten years and achieved remarkable achievements.There are many methods for preparing graphene.Compared with other synthesis methods,graphene thin films prepared by chemical vapor deposition(CVD)have the advantages of controllable number of layers(single layer or few layers),large area,and few defects.This paper firstly designed and prepared nickel / graphene(Ni / G)electrodes by plasma enhanced chemical vapor deposition(PECVD)for ultra-sensitive identification of D-phenylalanine and L-phenylalanine.Through the PECVD process,the Ni / G electrode can obtain better hydrophilicity and larger catalytic surface area,which is beneficial to its electrochemical recognition of biological objects.After surface modification with?-cyclodextrin,the ?-CD / Ni / G electrode can distinguish D-phenylalanine from L-phenylalanine according to the 0.09 V peak shift in the differential pulse voltammetry test.Moreover,the detection limit of the ?-CD / Ni / G electrode for L-phenylalanine is as low as 1nM,the linear range is from 1 nM to 10 m M,and it has good storage stability and working stability.Then the graphene film is prepared on the copper foil by chemical vapor deposition method,and the graphene is transferred by polymethyl methacrylate(PMMA)method.Select samples with excellent electrical properties to prepare graphene sensor devices,and explore the effects of blood components(serum,red blood cells,physiological saline,trace amounts of DNA)on the graphene sensor.Obviously,the Dirac point offset is 2 to 5.5 times that of other components and 2 times that of DNA.The effectiveness of a polymer ordered microporous membrane to screen red blood cells and its screening effect on red blood cells after being combined with a graphene sensor were verified.