Infra-Red Surface-Plasmon-Resonance technique for biological studies

TL;DR

This paper introduces an infrared surface plasmon resonance (SPR) technique utilizing a Fourier-Transform Infra-Red spectrometer, enabling simultaneous variation of wavelength and incident angle, enhancing biological molecule detection in aqueous solutions.

Contribution

The study develops a novel IR SPR setup with variable wavelength and angle, demonstrating improved sensitivity for biological studies over traditional visible-range SPR methods.

Findings

Infrared SPR sensitivity is higher than visible light SPR.

Optimal parameters for biological detection were identified through simulations.

Experimental validation confirmed the effectiveness of IR SPR in detecting glucose in biological fluids.

Abstract

We report on a Surface-Plasmon-Resonance (SPR) technique based on Fourier -Transform - Infra - Red (FTIR) spectrometer. In contrast to the conventional surface plasmon technique, operating at a fixed wavelength and a variable angle of incidence, our setup allows the wavelength and the angle of incidence to be varied simultaneously. We explored the potential of the SPR technique in the infrared for biological studies involving aqueous solutions. Using computer simulations, we found the optimal combination of parameters (incident angle, wavelength) for performing this task. Our experiments with physiologically important glucose concentrations in water and in human plasma verified our computer simulations. Importantly, we demonstrated that the sensitivity of the SPR technique in the infrared range is not lower and in fact is even higher than that for visible light. We emphasize the advantages of infra red SPR for studying glucose and other biological molecules in living cells.