Research And Application Of BSA-doped Graphene Field-effect Transistor Biosensors

Cancer,one of the major diseases endangering human health in today’s society,with lung cancer being the cancer with the highest number of deaths worldwide.Neuron-specific enolase(NSE)is the tumor marker of choice as an adjuvant diagnosis for small cell lung cancer and neuroblastoma.Therefore,improving the detection technology of NSE is of great value for the early screening and diagnosis of lung cancer.Graphene field-effect transistor(GFET)sensors are a kind of sensors widely used in biosensing detection in recent years,and doping graphene with proteins can help to enhance the performance of GFETs.In this paper,we prepared a thermo-denatured bovine serum albumin(BSA)-doped graphene field-effect transistor and successfully used it as a biosensor to detect the concentration of NSE.The main research works in this paper are as follows:1.Optimized the graphene wet transfer technology scheme to achieve high quality transfer of graphene on CVD copper foil.The BSA based on p H modulation to achieve different types of doping of graphene.Moreover,the abundant chemical groups on the surface of doped graphene provide convenience for biosensing.Optimized the preparation process of electrode evaporation coating,lithography and plasma treatment to improve the uniformity of photoresist coating.A transistor sample with high surface cleanliness and strong adsorption of gold electrode to the substrate was prepared.2.Preparation of doped GFETs by thermal denaturation of BSA-doped graphene,and the electrode insulation protection layer was prepared by photolithography process.Anti-NSE antibodies were modified on the surface of the doped graphene sensing channel by EDC and sulfo-NHS,resulting in biofunctionalization of the sensor.Electrical characterization tests verified the doping of graphene with BSA based on p H modulation,which achieved the modulation of graphene channel carrier concentration and enhanced the sensitivity and detection range of the graphene sensor.3.The detection and analysis of NSE using Anti-NSE-modified thermal denaturation BSA-doped GFET sensor.The detection results showed that the sensor has ultrahigh sensitivity,large detection range and fast response time for NSE,and the sensor has good specificity and recognition ability for NSE.The sensor has good specificity and recognition ability for NSE,and achieves the detection of NSE in serum with the advantages of high sensitivity and wide range,and the detection concentration range is 5 pg/m L～1 μg/m L.In summary,the Anti-NSE-modified thermal denaturation BSA-doped GFET sensor has high sensitivity,high specificity,good reproducibility and wide detection range for the detection of NSE.The successful detection of NSE by this sensor fills the technical gap of NSE detection by GFET sensors,and also provides a reference for the practical application of thermo-denaturing BSA-doped GFET sensors.