TY - JOUR
T1 - Size-Dependent Surface Enhanced Fluorescence of Gold Nanorod
T2 - Enhancement or Quenching
AU - Liaw, Jiunn Woei
AU - Tsai, Hsiao Yen
AU - Huang, Chun Hui
PY - 2012/9
Y1 - 2012/9
N2 - The size-dependent surface enhanced fluorescence (SEF) of a gold nanorod (GNR) on a vicinal molecule is studied systematically by using the multiple multipole method. The enhancement factors (EFs) of GNRs of different sizes (radius: a = 7 or 10 nm) with the same aspect ratio (AR), e. g., 3 or 3. 43, on the fluorescence of a molecule at different locations with various orientations excited at the longitudinal surface plasmon resonance (SPR) of a GNR are discussed in detail. The numerical results show that the EF of a GNR is sensitive not only to the molecular location and orientation but also to the size. The effective EF (EEF), the average of the EF over all possible orientations at a specific location, is further calculated. According to the EEF, the proximity of the end-cap of a GNR is a strong enhancing zone, while the waist area of the GNR is a relatively weak zone. Moreover, for the same AR, the EEF of a bigger GNR (a ≥ 10 nm) is larger than that of a smaller one. Hence, the SEF performance of a bigger GNR on the fluorescence can be a very strong enhancement if the molecule is close to the end-cup excited at the longitudinal SPR. On the contrary, the performance of a smaller GNR could be a quenching if the molecule is near the waist. In addition, the Stokes-shift effect of fluorescence on the EF is also discussed.
AB - The size-dependent surface enhanced fluorescence (SEF) of a gold nanorod (GNR) on a vicinal molecule is studied systematically by using the multiple multipole method. The enhancement factors (EFs) of GNRs of different sizes (radius: a = 7 or 10 nm) with the same aspect ratio (AR), e. g., 3 or 3. 43, on the fluorescence of a molecule at different locations with various orientations excited at the longitudinal surface plasmon resonance (SPR) of a GNR are discussed in detail. The numerical results show that the EF of a GNR is sensitive not only to the molecular location and orientation but also to the size. The effective EF (EEF), the average of the EF over all possible orientations at a specific location, is further calculated. According to the EEF, the proximity of the end-cap of a GNR is a strong enhancing zone, while the waist area of the GNR is a relatively weak zone. Moreover, for the same AR, the EEF of a bigger GNR (a ≥ 10 nm) is larger than that of a smaller one. Hence, the SEF performance of a bigger GNR on the fluorescence can be a very strong enhancement if the molecule is close to the end-cup excited at the longitudinal SPR. On the contrary, the performance of a smaller GNR could be a quenching if the molecule is near the waist. In addition, the Stokes-shift effect of fluorescence on the EF is also discussed.
KW - Enhancement factor
KW - Gold nanorod
KW - Longitudinal surface plasmon resonance
KW - MMP
KW - Plasmonic enhancement
KW - Quenching
KW - Surface enhanced fluorescence
UR - http://www.scopus.com/inward/record.url?scp=84865507374&partnerID=8YFLogxK
U2 - 10.1007/s11468-012-9341-9
DO - 10.1007/s11468-012-9341-9
M3 - 文章
AN - SCOPUS:84865507374
SN - 1557-1955
VL - 7
SP - 543
EP - 553
JO - Plasmonics
JF - Plasmonics
IS - 3
ER -