We study the interaction of gold nanoparticles with a graphene film. Graphene is used as a spacer, as thin as possible, between the gold nanoparticles and the detection dielectric medium, and one of the advantages of graphene is to protect the structure, which allows to avoid the oxidation of nanoparticles. We focus our study on the variation of the resonant structure (LSPR) depending on the thickness of the graphene layer (0.34-5 nm). A stronger resonance behavior of positions in the absorption spectrum shows a strong coupling between the LSP on gold nanoparticles and the covering film. Numerical simulations indicate a significant shift of the resonance wavelength structure SiO x /AuNPs/Graphene/SiO x (657.90 nm) compared with experimental results obtained on SiO x /AuNPs/SiO x (574.71 nm) and optimized for the required parameters proposed LSPR system we achieve the highest detection sensitivity range, while the location of points of the electric field on the best corners of the gold-graphene nanoparticles.

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We propose a new configuration of a localized surface plasmon resonance (LSPR) biosensor that is based on MoS 2 -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 MoS 2 /graphene on the Au nanoparticles or by adding the MoS 2 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 MoS 2 /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 MoS 2 and 10-layers of graphene. In addition, we show that the sensitivity can be controlled by changing the number of the monolayer of MoS 2 and/or graphene. Finally, we show that this sensor can detect successfully impure water after absorption of target single-stranded DeoxyriboNucleic Acid (ssDNA) biomolecules.

In this work, we propose a new configuration of the localized surface plasmon resonance (LSPR), based on MoS 2 hybrid structures for ultrasensitive biosensing applications. The plasmonic resonances are widely used in bimolecular detection and continue to be an active network because of the rich variety of surface configurations and measurement donations. The present work studies the interaction of gold nanoparticles with a MoS 2 film. MoS 2 is used as a thin spacer between the gold nanoparticles and the dielectric medium used for detection. MoS 2 monolayers have emerged recently as promising nanostructures for various applications in both the optics and electronics. This paper gives an overview of the optical properties of 2D nanostructures based on this new class of materials. A stronger behavior of the resonance positions in the absorption spectrum exhibits a strong coupling between the LSPR on the gold nanoparticles and the MoS 2 coating film. Numerical simulations display a significant red shift of the plasmonic resonance (λ max ) and the results show that using a 3.90 nm MoS 2 layer, the plasmon resonance wavelength is increased of 333.7 nm. We also study the performance of the proposed biosensors in terms of sensitivity using multilayers of MoS 2 , and normal incidence to the surface of SiO x /AuNPs/MoS 2 / water and SiO x /MoS 2 /AuNPs/water. We obtain a very high sensitivity of 297.62 nm/RIU corresponding to an increase of 26% compared to the results obtained on SiO x /AuNPs/water, with a location of the electric field on the gold nanoparticles and the covering MoS 2 layer. These characteristics should make these biosensors a preferred choice for detection applications.