Simple fabrication of one-dimensional metal nanostructures and their application for SERS analysis

This review highlights work using the author's method for the preparation of highly aligned metallic nanofibers with one-dimensional aggregates of metal nanoparticles (MNPs) and their utilization in surface enhanced Raman scattering (SERS) analysis. The preparation method, which is based on the process of evaporation-induced self-assembly with DNA and a drying front movement, eliminates the need for lithography and an external field; it is also fast, cheap and easy. Dark-field scattering spectroscopy was used to study the strong plasmon coupling of MNPs in metallic nanofibers. Furthermore, Raman spectral imaging of the metallic nanofibers revealed the existence of intense hot spots localized along their axes, which played a significant role in the intensity of SERS signals from DNA bases and rhodamine B in the metallic nanofibers. Our results demonstrate the use of evaporation-induced self-assembly with DNA as a straightforward method to produce the one-dimensional coupling of localized plasmons with a longer scale, and to facilitate the fabrication of optical sensor chips for single-molecule detection via SERS.