Optimized Vertical Carbon Nanotube Forests for Multiplex Surface-Enhanced Raman Scattering Detection.
The highly sensitive and molecule-specific technique of surface-enhanced Raman spectroscopy (SERS) generates high signal enhancements via localized optical fields on nanoscale metallic materials, which can be tuned by manipulation of the surface roughness and architecture on the submicrometer level. We investigate gold-functionalized vertically aligned carbon nanotube forests (VACNTs) as low-cost straightforward SERS nanoplatforms. We find that their SERS enhancements depend on their diameter and density, which are systematically optimized for their performance. Modeling of the VACNT-based SERS substrates confirms consistent dependence on structural parameters as observed experimentally. The created nanostructures span over large substrate areas, are readily configurable, and yield uniform and reproducible SERS enhancement factors. Further fabricated micropatterned VACNTs platforms are shown to deliver multiplexed SERS detection. The unique properties of CNTs, which can be synergistically utilized in VACNT-based substrates and patterned arrays, can thus provide new generation platforms for SERS detection.
†Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
Pola
P
Goldberg-Oppenheimer
‡Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
Tanya
T
Hutter
†Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
Bingan
B
Chen
†Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
John
J
Robertson
†Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
Stephan
S
Hofmann
§Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB30HE, United Kingdom.
Sumeet
S
Mahajan
multiplex detection; optimization; plasmons; surface-enhanced Raman spectroscopy (SERS); vertically aligned carbon nanotube (VACNT) forests