Multi-functional plasmonic bio-sensor based on alcohol-filled PCF

Abstract

An enhanced multifunctional biosensor based on surface plasmon resonance is proposed and studied based on alcohol mixture filled photonic crystal fiber (PCF). The suggested biosensor has an alcohol mixture housed into a central hole which operates as a temperature dependent material. In addition, a gold nano-rod is attached at the inner surface of a large hole which is infiltrated with the analyte under study. Accordingly, both analyte refractive index and temperature sensing can be achieved using the reported biosensor where the guided core modes in the central hole can be coupled to the surface plasmon modes around the gold nano-rod. The sensitivity of the proposed biosensor is maximized by studying the effects of the structure geometrical parameters. In this regard, full-vectorial finite element method is used throughout the numerical analysis with perfect matched layer boundary conditions. The multifunctional alcohol mixture filled PCF sensor achieves very high temperature sensitivity of 13.1 nm/℃ with very high analyte refractive index sensitivity of 12700 nm/RIU. According to the literature review, the achieved refractive index and temperature sensitivities are higher than those for similar recent sensors in the same sensing range.