Compact nanohole/disk array-based plasmonic fiber-optic end-facet sensing probe: batch preparation and performance determination

A gold nanohole/disk array-based plasmonic fiber end-facet sensing probe is proposed and demonstrated experimentally, where the hybrid plasmon mode on the top surface used for sensing is excited by the cooperative effect of the near-field coupling between the nanohole and the nanodisk, as well as the localized surface plasmon of the nanodisk.The high-quality integration of the nanohole/disk array on the fiber end facet is achieved by combining nanoimprint lithography on a planar substrate with fiber ultraviolet (UV)-curable adhesive transfer techniques.As a result, the fabricated fiber probe experimentally exhibits a moderately high bulk refractive index sensitivity of 196.91 nm/RIU and excellent surface sensitivity.Furthermore, the specific identification and determination of protein molecules verify their sensitivity analysis capabilities for future bioassays.This work provides a feasible plasmonic excitation strategy and enables batch-manufactured technology for nanostructure-based fiber probes to break through the current bottlenecks in biosensing applications.