Optical fiber sensor based on localized surface plasmon resonance using silver nanoparticles photodeposited on the optical fiber end.

J Gabriel Ortega-Mendoza,Carina Toxqui-Quitl,Placido Zaca-Morán,David Villegas-Hernández,Alfonso Padilla-Vivanco,Fernando Chávez

doi:10.3390/s141018701

Abstract

This paper reports the implementation of an optical fiber sensor to measure the refractive index in aqueous media based on localized surface plasmon resonance (LSPR). We have used a novel technique known as photodeposition to immobilize silver nanoparticles on the optical fiber end. This technique has a simple instrumentation, involves laser light via an optical fiber and silver nanoparticles suspended in an aqueous medium. The optical sensor was assembled using a tungsten lamp as white light, a spectrometer, and an optical fiber with silver nanoparticles. The response of this sensor is such that the LSPR peak wavelength is linearly shifted to longer wavelengths as the refractive index is increased, showing a sensitivity of 67.6 nm/RIU. Experimental results are presented.

Highlights

Sensors based on surface plasmon have been widely used to detect biological and chemical analytes, environmental control, and biomedical applications, among others [1,2,3,4,5,6]
We report the construction of an optical fiber sensor based on localized surface plasmon resonance (LSPR) phenomenon using silver nanoparticles
The LSPR peak wavelength is linearly shifted to longer wavelengths as far the refractive index is increased with a sensitivity of 67.5 nanometers per refractive index unit (nm/RIU)

Summary

Introduction

Sensors based on surface plasmon have been widely used to detect biological and chemical analytes, environmental control, and biomedical applications, among others [1,2,3,4,5,6]. Their main features are fast response, high sensitivity, and the detection is free-label [4,5]. Propagating surface plasmons are evanescent electromagnetic waves, which are propagating along of a flat metal-dielectric interface and they arise from oscillation of the conduction electrons whereas localized surface plasmons are non-propagating excitations of the conduction electrons of metal nanoparticles.

Deposition Method

Background

Photodeposition of Silver Nanoparticles on the Optical Fiber End

Measurement Setup

Results and Discussion

Conclusions