Surface-enhanced Raman scattering on periodic metal nanotips with tunable sharpness.
This paper reports on a scalable bottom-up technology for producing periodic gold nanotips with tunable sharpness as surface-enhanced Raman scattering (SERS) substrates. Inverted silicon pyramidal pits, which are templated from non-close-packed colloidal crystals prepared by a spin-coating technology, are used as structural templates to replicate arrays of polymer nanopyramids with nanoscale sharp tips. The deposition of a thin layer of gold on the polymer nanopyramids leads to the formation of SERS-active substrates with a high enhancement factor (up to 10(8)). The thickness of the deposited metal determines the sharpness of the nanotips and the resulting Raman enhancement factor. Finite-element electromagnetic modeling shows that the nanotips can significantly enhance the local electromagnetic field and the sharpness of nanotips greatly affects the SERS enhancement.
Linn
Nicholas C
NC
Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
Sun
Chih-Hung
CH
Arya
Ajay
A
Jiang
Peng
P
Jiang
Bin
B
D000465:Algorithms; D003198:Computer Simulation; D055590:Electromagnetic Phenomena; D020342:Finite Element Analysis; D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D012825:Silicon / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
D006046:Gold; D012825:Silicon