| Terahertz refers to electromagnetic wave which is between microwave and infrared ray,with frequency of 0.1-10 THz(wavelength between 30 um-3 mm).THz wave is special in electromagnetic spectrum: from long wave,it h as overlap with millimeter waves;from high frequency wave,it has overlap with infrared ray.THz is a peculiar region transferring from macroscopic classical theory and microscopic quantum theory,which has important value of research and application development.As strategy technology in 21 st century,THz has huge value in many science applications.These application domains consist of wireless communication,biomedical detection,noninvasive imaging with high resolution,materials characterization and so on.In this paper,taking the application of terahertz technology in the field of biomedical detection as the background,to study the photoelectric properties of graphene attached by bovine serum albumin under far infrared laser induced,the main research content is discussed from the following several aspects:This paper firstly research antireflective film which aims to improve the THz spectral resolution.Therefore we manufacte PEDOT/PSS thin film with different doping concentrations.According to Drude-Smith model,we study the conductivity of PEDOT/PSS which was doped by EG and explore the inner mechanism of variational conductivity.Then we prepare PEDOT/PSS thin film in different thickness on quartz substrate and discover that this film possesses well effect of antireflective and terahertz neutral filter mean at the same time.This anti-reflection film can be equipped in THzTDS to improve permeability of THz wave and resolution of spectrum.Next,with different band structure and electrical transport properties,graphene has important application value in the terahertz biosensor.When lasers of different wavelength pump silicon-based graphene,graphene's photoelectric properties undergo change,which provide theoretical support for the next test to bovine serum albumin under laser induced graphene.Under the excitation of the laser,photon-generated carriers can produce in silicon.When carrier concentration in silicon is greater than the graphene,carriers diffuse into graphene under the diffusion effect,which change the conductivity of graphene and the THz wave absorption of.graphene.Moreover,carriers caused by pump laser excitation can enhance the sensitivity of graphene's surface to attachments.This effect can be applied to guide the research for protein detection.In addition,the study found that the excitation of long wavelength laser increase THz wave attenuation,which provides a new consideration to develop better performance of THz wave modulator.Lastly,with excellent photoelectric properties,biocompatibility and sensitivity to surface attachments,biosensor based on graphene is often reported.The research about Terahertz spectroscopy which is used for biological detection has been carried out for many years,but THz spectrum with graphene as a platform for biological detection is relatively rare.In experiments,we attach the protein to graphene in two ways of spin coating and incubation,and data were obtained by transmission-type time-domain spectrometers under the excitation of infrared lasers.Drawing inspiration from THz transmission circuit model in the research part of anti-reflection film,the optical parameters of the graphene in the middle layer were extracted by using the deduced formula.The varieties of graphene's photoelectric properties were investigated.The graphene's application in terahertz biological detection was explored.In addition,we proposed a further solution about the qualitative and quantitative measurement of protein in order to catch up with the predecessors in terms of sensitivity. |
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