Studying Plasmonic Sensors and Optimizing Grating Shapes for Self-Referenced Sensor

Abstract

A plasmonic biosensor is an advanced technology that harnesses the principles of plasmonics and surface plasmon resonance (SPR) to detect and analyze biomolecular interactions in real time. Plasmonics involves the interaction between electromagnetic radiation (typically light) and free electrons on a metal's surface, resulting in the creation of surface plasmons—collective oscillations of the electron density. Surface plasmon resonance occurs when the resonant conditions for these surface plasmons are met, leading to a significant increase in the absorption and scattering of light. This study presents an investigation into the efficacy of self-referenced plasmonic biosensors utilizing different grating geometries, namely rectangular, trapezoidal, and triangular shapes. A comprehensive comparative analysis of these geometries was conducted through rigorous simulation studies using COMSOL Multiphysics software. The simulations, performed using advanced electromagnetic field solvers, provided insights into the electromagnetic interactions occurring at the sensor's surface. The findings revealed notable disparities in sensor performance based on grating geometry. Rectangular gratings exhibited higher sensitivity, making them suitable for detecting low analyte concentrations. Trapezoidal gratings demonstrated enhanced selectivity, with the ability to discriminate between different target molecules. Triangular gratings displayed a balanced performance in terms of sensitivity and selectivity. The self-referenced configuration further augmented the biosensor's accuracy by minimizing environmental noise effects. In conclusion, this study underscores the significance of grating geometry in tailoring the performance of self-referenced plasmonic biosensors. The comparative analysis highlights the strengths and weaknesses of each geometry and provides valuable insights for biosensor design optimization. This research contributes to the advancement of plasmonic biosensing technology, offering a guide for selecting the appropriate geometry based on specific application requirements.