Gold Nanospheres-Coated LSPR Fiber Sensor with High RI Sensitivity by a Rapid Fabricating Method

A simple, high performance Localized Surface Plasmon Resonance(LSPR) sensor was prepared by depositing gold nanospheres(AuNS) on the side wall of the optical silica fiber through electrostatic self-assembly method. The size and density of AuNS were optimized to investigate the best refractive index(RI) sensitivity. The results indicated that the RI sensitivities were increased with the increasing of size and density. The best RI sensitivity was about 2016.224 nm/RIU which was the highest in current LSPR fiber sensor study in visible wavelength range. Additionally, the high density AuNS monolayer was suitable for using as the Surface Enhanced Raman Scattering (SERS) substrate by measuring Raman signal of crystal violet. This fiber sensor will be expected to apply in the biochemistry detection.