A portable microcolumn based on silver nanoparticle functionalized glass fibers and its SERS application

We presented a facile method for the preparation of a portable detection column integrated with silver nanoparticle (Ag NP) functionalized glass fibers for surface-enhanced Raman scattering (SERS). Ag NPs were immobilized onto the surface of fibers through a two-step self-assembly process, and the cycling of the assembly process was repeated to optimize the SERS activity. The optimized fibers coated with homogeneous and dense Ag NPs were combined with a glass column, displaying good reproducibility. This combination could construct more "hot spots" and the spatial intra-channel structure for high mass transfer, and provide more sufficient interactions between the probing laser and metallic nanoparticles. The capability of the prepared column to have high sensitivity to dyes was demonstrated by the measurements of rhodamine 6G, alizarin red and methyl orange, with low concentrations of 28 pM, 64 pM and 0.36 nM, respectively. The SERS-active column fabricated by a facile, low-cost and high-yield approach is expected to be an effective and practical means for on-site application when rapid separation and detection of analytes in the liquid sample is needed.