Surface Enhanced Raman Spectroscopy (SERS) optical fibers for remote sensing

In this study, we present facile fabrication of a miniaturized remote sensing SERS platform using highly tunable Nano-Sphere Lithography (NSL) technique. Self-assembly at the air-water interface was performed and the monolayer of polystyrene spheres was transferred onto the tip of optical fibers. Various optical fibers with different numerical apertures (NAs) were used to find an optimal remote sensing setup. Using 200μm diameter optical fibers with high numerical aperture (0.5NA), the SERS enhancement of remote sensing was found to be 98% of direct sensing configuration. Standard silica optical fibers were used for remote sensing using SERS without additional need of optical filtering to mitigate fluorescence and Raman background of these fibers which allows fabrication of miniaturized remote sensing platforms that can be used for remote biochemical sensing.