Strong Coupling between Tamm and Surface Plasmons for Advanced Optical Bio-Sensing

Zigmas Balevičius

doi:10.3390/coatings10121187

Abstract

The total internal reflection ellipsometry method was used to analyse the angular spectra of the hybrid Tamm and surface plasmon modes and to compare their results with those obtained using the conventional single SPR method. As such type of measurement is quite common in commercial SPR devices, more detailed attention was paid to the analysis of the p-polarization reflection intensity dependence. The conducted study showed that the presence of strong coupling in the hybrid plasmonic modes increases the sensitivity of the plasmonic-based sensors due to the reduced losses in the metal layer. The experimental results and analysis of the optical responses of three different plasmonic-based samples indicated that the optimized Tamm plasmons ΔRp(TP) and optimized surface plasmons ΔRp(SP) samples produce a response that is about five and six times greater than the conventional surface plasmon resonance ΔRp(SPR) in angular spectra. The sensitivity of the refractive index unit of the spectroscopic measurements for the optimized Tamm plasmon samples was 1.5 times higher than for conventional SPR, while for wavelength scanning, the SPR overcame the optimized TP by 1.5 times.

Highlights

Sensors based on optical signal interrogation are widely used for the detection of biochemical interactions at solid–liquid interfaces, for the monitoring of various chemicals adsorbed on surfaces [1,2]and for the evaluation of the refractive indexes of liquids [3]
This rather strong light–matter interaction leads the properties of the dispersion relation (angular frequency (ω) and in-plane wavevector (k)) of the surface plasmon polaritons which are sensitive to the any perturbation of the refractive index changes on the Surface plasmon polariton (SPP) supported interfaces
Results and Discussions configuration and the so-called total internal reflection ellipsometry (TIRE), a higher sensitivity to has been shown that by applying ellipsometry in itsthat total internalby the Itrefractive index and before the attached surface mass spectroscopic can be achieved compared with produced reflection and the surface so-called total internal reflection ellipsometry (TIRE), asensitivity higher standard configuration commercially available plasmon resonance biosensors

Summary

Introduction

Sensors based on optical signal interrogation are widely used for the detection of biochemical interactions at solid–liquid interfaces, for the monitoring of various chemicals adsorbed on surfaces [1,2]and for the evaluation of the refractive indexes of liquids [3]. The first two slightly different photonic structures of hybrid plasmonic modes were optimized for distributed Bragg gratings consisting of 6 bilayers of ~120 nm TiO2/~200 nm SiO2 and a 30 nm TiO2 enhanced sensitivity of these particular excitation components (Tamm plasmons or surface plasmons). (Figure to demonstrate the optimized sensitivity properties in the angular spectra of the p-intensity polarizations for SPR and Tamm plasmon polaritons and hybrid TPP-SPP mode (Figure 4).

Results

Conclusion