Cylindrical posts of Ag/SiO₂/Au multi-segment layer patterns for highly efficient surface enhanced Raman scattering.
We fabricated a regular array of Ag/SiO₂/Au multi-segment cylindrical nanopatterns to create a highly efficient surface enhanced Raman scattering (SERS) active substrate using an advanced soft-nanoimprint lithographic technique. The SERS spectra results for Rhodamine 6G (R6G) molecules on the Ag/SiO₂/Au multi-segment nanopatterns show that the highly ordered patterns and interlayer thickness are responsible for enhancing the sensitivity and reproducibility, respectively, The multi-segment nanopattern with a silica interlayer generates significant SERS enhancement (~EF = 1.2 x 10⁶) as compared to that of the bimetallic (Ag/Au) nanopatterns without a dielectric gap (~EF = 1.0 x 10⁴). Further precise control of the interlayer distances between the two metals plays an essential role in enhancing SERS performance for detecting low concentrations of analytes such as fluorescent (Rhodamine 6G) and DNA molecules. Therefore, the highly ordered multi-segment patterns provide great sensitivity and reproducibility of SERS based detection, resulting in a high performance of the SERS substrate.
National Research Laboratory for Organic Opto-electronic Materials, Department of Chemical and Biomolecular Engineering-BK-21, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Kyoung Hwan
KH
Kim
Youn-Kyoung
YK
Baek
Hwan-Jin
HJ
Jeon
Mohan
M
Srinivasarao
Hee-Tae
HT
Jung
D004247:DNA / Q000032:analysis; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012235:Rhodamines / Q000032:analysis; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
D012235:Rhodamines; C026188:rhodamine 6G; D012834:Silver; D006046:Gold; D012822:Silicon Dioxide; D004247:DNA