Analysis of Fiber-Optic Localized Surface Plasmon Resonance Sensor by Controlling Formation of Gold Nanoparticles and its Bio-Application

Localized surface plasmon resonance (LSPR) occurs when nanoparticles are bound to the surface of a sensor which is sensitive to the refractive index of the surrounding medium. The sensitivity of the sensor is highly dependent on the type of nanoparticles and their size, density and shape. Using an optical fiber as a sensor has various advantages, such as guided signal delivery and low energy loss. In this study, a Fiber-optic localized surface plasmon resonance (FO-LSPR) sensor was developed and the sizes of the gold nanoparticles (Au NPs) used therein were controlled by reduction with chloroauric acid. The extinction cross-section was calculated by the Mie theory to examine the dependence of the resonance intensity and sensitivity of the fabricated FO-LSPR sensor on the size and density of the Au NPs situated on its end-face. In order to use it as a biosensor, the fabricated FO-LSPR sensor was used to detect the biotin-streptavidin interaction.