Coaxial nanowires as plasmon-mediated remote nanosensors

Abstract

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 of a gold core to propagate 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 the remote-Raman effect, the original hard template-based process allows one 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.

Sub-Micron Spatial Resolution in Far-Field Raman Imaging Using Positivity-Constrained Super-Resolution

“…Interior-point least squares was applied to Raman spectroscopic data acquired from a bundle of nanowires made of poly-(3,4 ethylenedioxythiophene) here referred to as PEDOT. 19,20 Atomic force microscopy (AFM) images were obtained from the same sample area. Atomic force microscopy imaging is not affected by the optical diffraction limit and hence provides a means to evaluate the quality of the super-resolved Raman images.…”

Nanoscale Spatial Resolution in Far-Field Raman Imaging Using Hyperspectral Unmixing in Combination with Positivity Constrained Super-Resolution

“…The power of the approach and methodology were demonstrated on Raman spectroscopic data from a bundle of nanowires made of poly-(3,4 ethylenedioxythiophene) (PEDOT). 25 The HyRes methodology of this paper resulted in an order of magnitude better spatial resolution than past works on SRIR of Raman data 9–13 and a 25× enhanced spatial resolution when compared to the raw far-field data.…”

“…Sample preparation, acquisition of sample data and the Raman microscope's response function, and single channel super-resolution are described in detail in previous work. 12,25 The PEDOT nanowires have diameters of (100±10)nm. The Raman microscope's response function is a 2D Gaussian with full width half-maximum (FWHM) of in horizontal (FWHMx) and vertical (FWHMy) focal plane direction, respectively.…”

Refined RGB Strategy for the Synthesis of Polymer‐Based Full Organic Luminescent Nanotubes with Broad Emission Bands

“…They are straightforward from an engineering point of view, scalable, cheap in processing, and can be fabricated quickly since a controlled self-assembled growth can be implemented. [23][24][25][26][27][28][29][30][31][32][33] Amongst the various possibilities offered by luminescent nano-objects, light-emitting polymer nanotubes have received close attention due to their potential to be operated integrable nanometer-scale light sources. [34] As mentioned above, certain types of light-emitting polymer nanotubes and nanowires have already been reported using luminescent conjugated and dopant-activated polymers as building materials.…”