Comparison of sensitivity of the refractometric methods of frustrated total internal reflection and surface plasmon resonance

2020 ◽  
pp. 44-49
Author(s):  
I. N. Pavlov

Two optical methods, namely surface plasmon resonance imaging and frustrated total internal reflection, are described in the paper in terms of comparing their sensitivity to change of refractive index of a thin boundary layer of an investigated medium. It is shown that, despite the fact that the theoretically calculated sensitivity is higher for the frustrated total internal reflection method, and the fact that usually in practice the surface plasmon resonance method, on the contrary, is considered more sensitive, under the same experimental conditions both methods show a similar result.

2013 ◽  
Vol 746 ◽  
pp. 564-569
Author(s):  
Shinn Fwu Wang ◽  
Ting Huan Chen ◽  
Pei Cheng Ke ◽  
Yi Chu ◽  
Yu Pin Liao ◽  
...  

In this paper, a z-axis displacement sensor based on Total-Internal Reflection and Surface Plasmon Resonance in heterodyne interferometry is proposed. The sensing unit is composed of a parallelogram prism, i.e. elongated prism, and a displacement probe. One side surface of the elongated prism was coated with a 2 nm Ti-film and a 45.5 nm Au-film, but the other side surface of that were not coated with metal films. The z-axis displacement sensor is with high sensitivity and resolution due to multiple attenuated total reflections and total internal reflections effects. Besides, we can obtain the results of the experiment in a distant place by uses of the USB data acquisition card (DAQ card) and a ZigBee module. In fact, the displacement resolution of the z-axis displacement meter can reach sub-nanometer by numerical simulation. The small-displacement sensor has some merits, e.g., in real-time test, easy operation, high measurement accuracy, high resolution, etc.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kyeong Rim Ryu ◽  
Geun Wan Kim ◽  
Ji Won Ha

AbstractPlasmonic gold nanoparticles are widely used in localized surface plasmon resonance (LSPR) sensing. When target molecules adsorb to the nanoparticles, they induce a shift in the LSPR scattering spectrum. In conventional LSPR sensing, this shift is monitored at the maximum of the LSPR scattering peak. Herein, we describe the sensitivity of detecting chemisorption of 1-alkanethiols with different chain lengths (1-butanethiol and 1-haxanethiol) on single gold nanorods (AuNRs) of fixed diameter (25 nm) and three different aspect ratios under a total internal reflection scattering microscope. For single AuNRs of all sizes, the inflection point (IF) at the long-wavelength side (or low-energy side) of the LSPR scattering peak showed higher detection sensitivity than the traditionally used peak maximum. The improved sensitivity can be ascribed to the shape change of the LSPR peak when the local refractive index is increased by chemisorption. Our results demonstrate the usefulness of tracking the curvature shapes by monitoring the homogeneous LSPR IF at the red side of the scattering spectrum of single AuNRs.


Sign in / Sign up

Export Citation Format

Share Document