The Fabrication and SERS Performance of Multi-layer Hollow Au-Ag Alloy Nano Urchins Structure-based SERS Fiber Probe

Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method, and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication. The nano urchins homogeneously distributed on fiber surface because of fiber silanization. The sizes and tip sharpness of the nano-urchins could be controlled by Ag seeds. The elements distribution analysis indicated there was high Ag content in tip-top for better surface enhance Raman scattering performance. The detectable concentration could be as low as 10 −8 M using crystal violet molecules as analyte. Moreover, the fiber probes were stable in air, due to Au in the alloy. This fiber probe could be used for low content single molecular analysis.