Graphene-Based Biosensors for Detection of Composite Vibrational Fingerprints in the Mid-Infrared Region.

Yijun Cai,Yuanguo Zhou,Jingwen Yang,Xuanyu Wang,Yanfen Hang,Jinfeng Zhu

doi:10.3390/nano9101496

Abstract

In this study, a label-free multi-resonant graphene-based biosensor with periodic graphene nanoribbons is proposed for detection of composite vibrational fingerprints in the mid-infrared range. The multiple vibrational signals of biomolecules are simultaneously enhanced and detected by different resonances in the transmission spectrum. Each of the transmission dips can be independently tuned by altering the gating voltage applied on the corresponding graphene nanoribbon. Geometric parameters are investigated and optimized to obtain excellent sensing performance. Limit of detection is also evaluated in an approximation way. Besides, the biosensor can operate in a wide range of incident angles. Electric field intensity distributions are depicted to reveal the physical insight. Moreover, another biosensor based on periodic graphene nanodisks is further proposed, whose performance is insensitive to the polarization of incidence. Our research may have a potential for designing graphene-based biosensor used in many promising bioanalytical and pharmaceutical applications.

Highlights

Surface plasmon resonance (SPR) biosensors have received tremendous attention over the past decades due to their label-free sensing ability [1,2]
Transmittance spectra of multi-resonant graphene-based biosensor (MRGB) under mid-infrared incidence are plotted in Figure 2 to investigate the detection capacity for composite vibrational fingerprints of multiple biomolecules
Two obvious transmission dips are observed in the spectra under TMincidence, which is able to induce the electrons to vibrate in the finite width of graphene nanoribbons (GNRs) due to its electric field direction

Summary

Introduction

Surface plasmon resonance (SPR) biosensors have received tremendous attention over the past decades due to their label-free sensing ability [1,2] They utilize surface plasmon polariton (SPP) waves to detect the refractive index (RI) change in the sensing surface produced by the alteration of biomolecule concentration. Vibrational signals in minute amounts of analytes are quite weak due to the mismatch between nanometric size of biomolecules (

Methods

Results

Conclusion