Graphene‐Coated Gold Chips for Enhanced Goos–Hanchen Shift Plasmonic Sensing

Abstract

Plasmon‐based sensing relies on the interaction of photons with nanostructured materials. Surface plasmon resonance (SPR) biological and chemical sensors offer unique advantages of real‐time and label‐free detection techniques and therefore, they have been around in the commercial market for many decades. The principle of the Goos–Hanchen (GH) shift, whereby linearly polarized light undergoes a small lateral shift upon total internal reflection at a dielectric surface, is highly sensitive to refractive index (RI) changes in the sensing medium and can thus be utilized for plasmonic sensing. 2D materials such as graphene can boost the plasmonic efficiency of these sensors because of their excellent optical properties. Herein, a customized GH shift–based SPR sensor is devised using graphene‐coated Au chips. With the help of experimental results, it is shown that graphene can enhance the sensitivity of the conventional Au‐only configuration 2.35 times.

Computational Modeling for Intelligent Surface Plasmon Resonance Sensor Design and Experimental Schemes for Real‐Time Plasmonic Biosensing: A Review

“…GH shift sensing methodology is employed to evaluate the sensitivity enhancement of graphene‐coated Au chips. [ 133 ] A customized setup was used that consisted of a laser source, a polarizer, the sensing chip attached to the prism, and a position detector. Briefly, the change in GH shift was calculated by measuring the difference in the x coordinate of the p‐polarized reflected light for de‐ionized (D.I.)…”

Goos–Hänchen shift for coupled vibrational modes in a semiconductor structure

“…It has also been shown that the sensitivity of bimetallic sensors based on the graphene-hexagonal boron nitride heterostructure can be enhanced by increasing the GHS in the infrared band [7]. Likewise, giant GHS has been predicted theoretically [8][9][10][11] and demonstrated experimentally [12][13][14][15]. In a recent experiment, Sreekanth et al demonstrated a thirtyfold enhancement in GHS at the Brewster angle of a nanophotonic cavity operating at a given wavelength [12].…”

Preparation of low-dimensional materials for plasmonic bio-sensing

“…Figure 10.3 Optics experiment instruments and setup for the GH shift estimation of the Au and Au + graphene based SPR sensors 130. reflected light to the change in R.I. of the analyte layer.…”

“…reflected light to the change in R.I. of the analyte layer. For the bio-molecular sensing experiment, the experiment procedure remains the same except that we use Phosphate buffered saline (PBS) buffer and 0.25 mg/mL BSA in PBS as the analyte for the first and second sets respectively 130. GHp(Theta)=x_positionp(Theta)|0.1%glycerol-x_positionp(Theta)|D.I.…”

“…Figure 10.4 (a) Photograph of graphene film transferred on the gold chip. (b) Raman spectra of graphene on the gold surface 130. …”