Detection Of Protein Secondary Structure By Acoustic Graphene Surface Plasmon Resonance

As an important branch of micro-nano photonics,surface plasmon technology has attracted many scholars to study it,and has achieved rich research results,which has made great contributions to promoting the progress of science and technology.Graphene has excellent properties such as low transmission loss and strong field confinement,and has important applications in the fields of optoelectronics,super-surfaces,energy utilization and spectroscopy.When graphene and metal are stacked reasonably,symmetrical heterogeneous charge oscillations are excited in the range of incident infrared band,and then the acoustic graphene plasmons(AGPs)resonance phenomenon can be excited.Moreover,graphene has a wide range of applications in biosensors due to its tunability,better stability,nonlinear characteristic,photoelectric properties and biomacromolecule adsorption capacity.Protein is indispensable components of cells,and many diseases have been found to be associated with abnormal secondary structure of protein,so the detection of their structure is important for medical detection and diagnosis.In view of this,the present studies are of great research value in the detection of protein secondary structures using graphene/metal periodic structures and the resonance properties of AGPs.Firstly,from the perspective of surface plasmon,the research status of acoustic graphene plasmons resonances is mainly analyzed.It is found that the phonon excitons supported by AGPs have lower transmission energy loss than metal conductors.Then,the fabrication method and optical properties of graphene are analyzed.Secondly,the acoustic graphene plasmon resonator based on gold nanowire array is proposed.The purpose of high concentration of field energy is achieved,the loss of energy is reduced and the interaction between incident light and measured material is enhanced.The structural parameters of the resonator are optimized by combining the finite difference time domain method,a tunable refractive index sensor is proposed.The detection range,accuracy,sensitivity and other performance parameters of the resonator are determined.Finally,this resonator is applied to the detection of protein secondary structure,and it is found that when the AGPs resonance phenomenon is combined with the mid-infrared spectroscopy technique,strong and effective coupling efficiency and high optical localization between light and trace substances are excited.In this paper,the designed AGPs biosensor is used to numerically simulate the secondary structure of the specified protein in dry and water environments.The feasibility is verified by observing the signal.Combined with the diversity of the detectable range,the effect of spatial scanning is achieved and the detection efficiency is improved.It has a broad application prospect in biological probes,medical detection and other disciplines.