Study On Metamaterial Resonance Microstructure Biosensor

Metamaterials have unique electromagnetic properties that can flexibly control electromagnetic waves to achieve unique electromagnetic properties that other materials do not have,and it has potential application prospects in many fields,which has attracted extensive attention from researchers.Metamaterial sensors usually achieve a strong local field through the plasmon resonance effect,which can effectively improve the sensing signal and realize highly sensitive detection of the surface dielectric environment.Compared with traditional sensing,metamaterial sensing has many advantages such as fast response,high sensitivity,label-free,real-time monitoring and simple measurement.Graphene is a two-dimensional material which is composed of sp²hybridized carbon atoms,which can adsorb biomolecules well and shows extraordinary potential in biosensing.This article is based on the principle of Rabbi split resonance.A metal-graphene hybrid metamaterial is designed.In addition,the two metamaterial resonance micro-structures are also designed with the principle of toroidal dipole resonance,and the two resonance mechanisms are studied.At the same time,the three metamaterial microstructures were prepared by standard photolithography process,and combined with Terahertz Time-domain Spectroscopy system as biosensor devices,Aβ_16-22polypeptide,gutter oil,aflatoxin B1 were detected.Essence The specific research content of the article is as follows:First,we combined simulation software to design a hybrid metamaterial composed of metal grating and surface graphene.Under the excitation of terahertz waves,the graphene on the surface of the metamaterial can excite the resonance of surface plasmons,and the metal grating can form an extraordinary optical transmission effect,and these two resonance modes will be strongly coupled when the graphene doping matches the parameters of the metal grating to form a new resonance mode which is Rabi split.The hybrid metamaterial was prepared from the experiment by us,which was applied to the agglomeration process of Aβ_16-22peptide.Aβ_16-22peptide with different agglutination states will cause different graphene doped state on the surface of the metamaterial,which will cause changes in graphene Fermine.These changes will be sensitive to Rabi split of hybrid metamaterials On the spectrum.We used molecular dynamic simulation to proposeπ-πbond stacking to explain the changes in the graphene pelid energy level in the process of Aβ_16-22peptide,and verified the correctness of our theory through the Raman spectrum.Secondly,based on the toroidal dipole resonance principle,we designed and prepared a mirror-symmetrical square double-split ring structure toroidal dipole metamaterial sensor,which generated a transmission resonance dip with a Q value of16.8 at 1.436 THz.The analysis of the surface current of the structure at the resonant frequency shows that the structure can rapidly strengthen the toroidal dipole while suppressing the electric and magnetic dipoles.As a biosensor,it has a sensitivity of up to 348.8 GHz/RIU when the analyte thickness is saturated,and can sensitively detect small changes in the surface dielectric environment.Different oil samples were experimentally measured,and the experimental results verified its good resolution between standard edible oil and inferior gutter oil,indicating the potential application prospect of the device in food safety monitoring.In the end,we also designed a high sensitive semicircular mirror-symmetrical metamaterial sensor based on the theory of toroidal dipole resonance theory,which formed a sharp transmission dip with a Q value of 26.6 at 1.33 THz.The refractive index sensitivity at a saturated thickness analysis is as high as 337.5 GHz/RIU.In the experiment,we used the metamaterial device to detect different concentrations of aflatoxin B1,indicating that it can achieve high-sensitive bidds without standard detection in the Tahertz field,which enriches the terahertz metamaterial sensor.