Study Of Hemoglobin Detection Using Graphene Field Effect Transistor Nanosensor

In recent years,the prevalence of chronic diseases has increased dramatically,threatening human health and affecting people’s quality of life.The existing clinical detection technology is expensive and time-consuming,which cannot realize the low-cost and rapid detection of chronic diseases.Graphene Field Effect Transistor(GFET)nanobiosensor has the advantage of high sensitivity and fast response,which has broad application prospects in disease prevention and diagnosis.The design and fabrication of the solution-gated GFET nanobiosensor with a planar gate based on the aptameric GFET sensor for detection of biomarkers is presented in this thesis.This dissertation studies the effect of the nucleic acid aptamer-protein affinity binding on the carrier concentration in graphene and the position of the Dirac point using theoretical analysis and experiments,thereby revealing the sensing mechanism of the GFET nanobiosensor on the protein biomarker detection.Establishing the mathematic model between the GFET nanobiosensor response signal and protein concentrations using Hill equation and GFET transport characteristics,providing the theoretical and experimental support for explaining the nucleic acid aptamer-protein affinity binding effect on the drain-source current through graphene.Hemoglobin molecule is taken as the main research object in this thesis.The detection experiments of the hemoglobin biomarker using the GFET nanobiosensor are carried out in artificial(PBS)and biological(Serum)fluids in order to prove the good binding affinity of the aptamer to the protein molecule.Raman spectroscopy,EDS characterization and electrical detection were used to characterize PASE functionalization,nucleic acid aptamer modification and bare graphene.