Optimizing metal nanoparticle spacing for enhanced interchangeability of tapered fiber SERS probes

This study addresses the low interchangeability of tapered fiber SERS probes produced through cost-effective chemical synthesis techniques, which complicates quantitative SERS detection. We investigate the impact of nanoparticle spacing variations on the interchangeability of these probes and propose a method to enhance it by optimizing nanoparticle spacing. Our approach demonstrates that increasing the average separation between 70 nm gold spherical nanoparticles to 100 nm significantly improves interchangeability, achieving a relative standard deviation of 5.21% in the measured SERS spectral amplitude, while maintaining high sensitivity in SERS detection. The effectiveness of our enhancement method is validated using tapered multimode-fiber SERS probes self-assembled by electrostatic adsorption.