  This study reports on the plasmon-mediated remote Raman sensing promoted by
specially designed coaxial nanowires. This unusual geometry for Raman study is
based on the separation, by several micrometres, of the excitation laser spot,
on one tip of the nanowire, and the Raman detection at the other tip. The very
weak efficiency of Raman emission makes it challenging in a remote
configuration. For the proof-of-concept, we designed coaxial nanowires
consisting in a gold core to propagate the surface plasmon polaritons and a
Raman-emitting shell of poly(3,4-ethylene-dioxythiophene). The success of the
fabrication was demonstrated by correlating, for the same single nanowire, a
morphological analysis by electron microscopy and Raman spectroscopy analysis.
Importantly for probing remote-Raman effect, the original hard template-based
process allows to control the location of the polymer shell all along the
nanowire, or only close to one or the two nanowire tips. Such all-in-one single
nanowires could have applications in the remote detection of photo-degradable
substances and for exploring 1D nanosources for integrated photonic and
plasmonic systems.
