Simulating a graphene-based acousto-plasmonic biosensor to eliminate the interference of surrounding medium

Area of Science:

• * Plasmonics and Nanophotonics
• * Biosensing Technologies
• * Graphene-based Devices

Background:

• * Refractive index biosensors using surface plasmon resonances (SPRs) are susceptible to measurement ambiguity from interfering species in the analyte.
• * Distinguishing target biomolecules from other substances is crucial for accurate biosensing.
• * Graphene's unique properties offer dynamic tunability for enhanced biosensor performance.

Purpose of the Study:

• * To propose and numerically investigate two methods for eliminating ambiguity in graphene-based acousto-plasmonic biosensor measurements.
• * To demonstrate the decoupling of target analyte signals from non-target species.
• * To assess the impact of various operational and material parameters on biosensor sensitivity and specificity.

Main Methods:

• * Development of graphene-based acousto-plasmonic biosensors utilizing surface acoustic waves (SAWs).
• * Method 1: Employing dynamic tunability of graphene SPRs via applied voltage with SAW-induced uniform gratings.
• * Method 2: Utilizing SAW-induced dual-segment gratings for a single-measurement approach.

Main Results:

• * Both proposed methods effectively decouple the target analyte's effect from other species, enabling unambiguous measurement interpretation.
• * Numerical investigations confirmed the capability of the biosensors to minimize cross-sensitivities to non-target biomolecules.
• * Analysis revealed the influence of parameters like graphene Fermi energy and target layer properties on sensing characteristics.

Conclusions:

• * The proposed graphene-based acousto-plasmonic biosensors offer robust solutions for overcoming measurement ambiguity in complex samples.
• * These advanced biosensing platforms show significant promise for next-generation lab-on-a-chip devices.
• * The developed methods enhance the reliability and specificity of biosensing, crucial for diagnostic and analytical applications.