Numerical Simulation Study On The Surface Plasmon Resonance Effect Of Nanohole Arrays

The development of nano-optical technology and the continuous improvement of the production level of nano-devices have greatly promoted the research of surface plasmons,which has led to rapid development in many fields such as nanophotonics,integrated optical devices,and biosensors.,And extended many new research directions.At present,surface plasmon-based sensors have reached maturity.They can indirectly detect the molecules adsorbed on the surface of the device based on changes caused by changes in the local refractive index.They can also use enhanced optical near-fields based on the interaction of different light and matter.Principle of action,direct detection of molecules.At present,surface plasmon devices for detecting the state of molecules with redox properties have not been widely developed,especially for redox proteins in living organisms.Therefore,in response to this need,this article uses cytochrome-c protein as the target biomolecule to study surface plasmon biosensors.This protein is an important link in the respiratory chain.Its main function is to transfer electrons between mitochondrial membrane proteins.It has been clinically used to treat hypoxia symptoms caused by cellular respiratory disorders.Therefore,it is studied in the oxidation state and reduction The characteristics and laws of the transition between states have very important biological and medical significance,and the development of biosensors capable of detecting the state of redox proteins will provide theories for revealing pathogenic mechanisms,disease detection,and new drug development related to such biomolecules.Basic and technical support.This article first introduces the development history and principle of surface plasmons in detail,the super-transmission phenomenon of surface plasmons,and then designs a numerical simulation model based on CMOSOL software by using grating coupling to excite surface plasmons.Two nano-hole array models based on gold film and aluminum film are simulated.The simulation results show:(1)The gold film-based model realizes the adjustment of the resonance frequency,resonance wavelength,resonance intensity and quantity of the transmission peak in the visible light and near-infrared bands by changing the model period and the size of the hole diameter.By changing the polarization direction and adding nanometers The comparison model simulation of the slot chain realizes the blue shift of the transmission resonance peak,obtains the transmission spectrum with a narrower half-width,and optimizes the experimental model.Through the analysis of the transmission peaks,the causes and change factors of the transmission peaks are explained.(2)By simulating the aluminum film-based model and numerically fitting the super transmission peak,the goal of the maximum difference between the resonance frequency of the surface plasmon and the absorption spectrum of cytochrome-c in the oxidation state and the reduction state is achieved.Therefore,it is expected that the model can be actually manufactured,and the dynamic conversion process of the redox state of cytochrome-c can be detected indirectly through dynamic measurement of transmission spectra.This simulation work provides the necessary theoretical basis for the development of surface plasmon biosensors for molecules with redox properties.