Plasma-induced formation of Ag nanodots for ultra-high-enhancement surface-enhanced Raman scattering substrates.
We report here plasma-induced formation of Ag nanostructures for surface-enhanced Raman scattering (SERS) applications. An array of uniform Ag patterned structures of 150 nm diameter was first fabricated on a silicon substrate with imprint lithography; then the substrate was further treated with an oxygen plasma to fracture the patterned structures into clusters of smaller, interconnected, closely packed Ag nanoparticles (20-60 nm) and redeposited Ag nanodots ( approximately 10 nm) between the clusters. The substrate thus formed had a uniform ultrahigh SERS enhancement factor (1010) over the entire substrate for 4-mercaptophenol molecules. By comparison, Au patterned structures fabricated with the same method did not undergo such a morphological change after the plasma treatment and showed no enhancement of Raman scattering.
Li
Zhiyong
Z
Quantum Science Research, Hewlett-Packard Laboratories, 1501 Page Mill Road, Palo Alto, California 94304, USA. zhiyong.li@hp.com
Tong
William M
WM
Stickle
William F
WF
Neiman
David L
DL
Williams
R Stanley
RS
Hunter
Luke L
LL
Talin
A Alec
AA
Li
D
D
Brueck
S R J
SR
D000327:Adsorption; D049329:Nanostructures / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D010316:Particle Size; D010636:Phenols / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
C505584:4-mercaptophenol; D010636:Phenols; D013438:Sulfhydryl Compounds; D012834:Silver; D010100:Oxygen; D012825:Silicon