Research On Detection And Analysis Of Protein Molecular By Terahertz Time-domain Spectroscopy

Teraherz(THz) radiation is ground into the region from 0.1 THz to 10 THz. This radiation contains a wealth of spectral information related to molecules’ vibration and rotation. As a precious spectrum resource, terahertz technology has achieved a worldwide attention and effective applied in several field include security scanner, communications and seed analysis for agriculture. In the recent years, many previous studies have proved the collective structural vibrational mode of protein like skeletal vibration and configuration bending. And these vibrational modes are thought to be essential for conformational dynamics of protein function, which allows the probing biological materials to get the information of the structure of biological macromolecules, molecular reaction and molecular interaction with the environment, etc. Therefore, there have a further requirements for apply terahertz technology applications in the fields of molecular biology, structure chemistry and clinical testing.In this paper, our work can be divided into three parts:Firstly, THz-TDS has been used to measure spectrum of hemagglutinin(HA) protein solution and the reaction with its specific antibody and nonspecific antibody in room temperature. Chemical calculation methods were employed to qualitative and quantitative analysis and identify the optimal parameters and optimum spectral preprocessing methods according to different optical parameters of these samples. As a result, we demonstrated that the combination of pretreatment and principal component analysis of spectrum is an available way to qualitative and quantitative analysis in terahertz region.Then based on the optimal parameters, we used THz-TDS to study the molecular dynamic hydration shell of hemagglutinin(HA) protein with different concentration and detected of the combination of hemagglutinin protein antigen and broadly neutralizing monoclonal antibody(F10). The experience data showed that the dielectric loss tangent of HA-F10 solution in terahertz frequencies can realize high-sensitive antigen-antibody banding detection that much more sensitive than traditional detect method.Lastly, based on the principles of graphene band gap control, the detection mathematical model of graphene terahertz detector is established. A graphene nanoribbons terahertz detector is designed and some parameters of nanoribbon are optimized by the finite element software COMSOL Multiphysics in terahertz region. The simulation result demonstrated that the transmittance of terahertz radiation would change orderly with the change of protein’s refractivity.