MoS2–graphene hybrid nanostructures enhanced localized surface plasmon resonance biosensors

Mohamed El Barghouti,Abdellatif Akjouj,Abdellah Mir

doi:10.1016/j.optlastec.2020.106306

Abstract

We propose a new configuration of a localized surface plasmon resonance (LSPR) biosensor that is based on MoS2–graphene hybrid structures for ultrasensitive detection of molecules. The performance parameters of the proposed biosensor are defined in terms of absorption and sensitivity. Our study show that sensitivity can be greatly increased either by adding a bilayer MoS2/graphene on the Au nanoparticles or by adding the MoS2 layer or the graphene layer on the surface of the Au nanoparticles. The absorption curves for the proposed LSPR biosensor are analyzed and compared with the conventional biosensors without MoS2/graphene. By optimizing the structure of the sensor, we find that the sensitivity as high as 360 nm/RIU can be achieved with 8-layers of MoS2 and 10-layers of graphene. In addition, we show that the sensitivity can be controlled by changing the number of the monolayer of MoS2 and/or graphene. Finally, we show that this sensor can detect successfully impure water after absorption of target single-stranded DeoxyriboNucleic Acid (ssDNA) biomolecules.

Highlights

The optical properties of metal nanoparticles and their addressability by spectroscopic techniques have put them at the forefront of the fundamental and applied fields of research, with applications ranging from nanoscale wave guidance to localized surface plasmon resonance (LSPR) biosensor designs, for the biological and chemical detection [1,2,3,4]
We have theoretically examined a new type of biosensor structure based on the configuration of a highly sensitive hybrid LSPR sensor AuNPs/MoS2/Graphene
It is found that the introduction of the MoS2 layer and the graphene layer can significantly improve the sensitivity of the biosensor as the conventional LSPR sensor

Summary

Introduction

The optical properties of metal nanoparticles and their addressability by spectroscopic techniques have put them at the forefront of the fundamental and applied fields of research, with applications ranging from nanoscale wave guidance to localized surface plasmon resonance (LSPR) biosensor designs, for the biological and chemical detection [1,2,3,4]. The understanding of the properties of the gold nanoparticles (AuNPs) is significantly more complex when the AuNPs are deposited on a substrate [1,5,6] and/or when the interaction between the AuNPs and the substrate is not neglected [7,8,9] It is quite clear from the theoretical and experimental studies on the AuNPs that several parameters govern their behavior [10,11]. LSPR nanostructure with periodic gold nanoparticles (AuNPs) on a substrate has been suggested to improve sensitivity [12,13]. This approach could be used as an effective means of increasing the reaction surface and generating a very confined localized surface plasmon mode, and enhancing a polarized field-nanoparticle interaction [8]. In order to improve the sensitivity, there are several approaches for improving the adsorption of biomolecules, e.g. the growth of an affinity layer [14,15], using two-dimensional (2D) nano-layers of MoS2 and graphene on AuNPs [16,17,18,19]

Methods

Findings

Discussion

Conclusion