Gold Nanoparticles-Modified Tapered Fiber Nanoprobe for Remote SERS Detection

This letter presents a surface-enhanced Raman scattering (SERS) nanoprobe based on gold nanoparticles-modified tapered optical fiber and demonstrates its ability to perform remote Raman detection. The nanoscale tapered fiber with the tip size of 40.7 nm was made by heated pulling and chemical etching methods. The gold nanoparticles, prepared beforehand by the Frens method with a microwave heating process, were deposited on the tapered surface of the nanoprobe with the electrostatic self-assembly technology. Raman spectra of Rhodamine 6G (R6G) molecules were measured, using this SERS nanoprobe in an optrode remote detection mode. Considerably high signal-to-noise ratio and high sensitivity were achieved. The detection limit for R6G aqueous solution reaches 10^-8 mol/L.