TY - JOUR
T1 - Plasmonic enhancement and polarization dependence of nonlinear upconversion emissions from single gold nanorod@SiO2@CaF2:Yb3+, Er3+ hybrid core-shell-satellite nanostructures
AU - He, Jijun
AU - Zheng, Wei
AU - Ligmajer, Filip
AU - Chan, Chi Fai
AU - Bao, Zhiyong
AU - WONG, Ka-Leung
AU - Chen, Xueyuan
AU - Hao, Jianhua
AU - Dai, Jiyan
AU - Yu, Siu Fung
AU - Lei, Dang Yuan
N1 - Funding Information:
We acknowledge the financial support by the Hong Kong Research Grants Council (GRF Grant No. 15301414). FL acknowledges the support by the Ministry of Education, Youth and Sports of the Czech Republic under project CEITEC 2020 (LQ1601) and by the Hong Kong Polytechnic University. XC and WZ acknowledge the financial support by the NSFC (Nos. U1305244, 21325104, 11304314) and the CAS/SAFEA International Partnership Program for Creative Research Teams. JH thanks Mr. Gongxun Bai and Mr Ming-Kiu Tsang for assistance in using the Edinburgh FLS920 Fluorescence Spectrometer. JH also thanks Zijian Zheng and Xiaoling Wei for assistance in the zeta-potential measurements.
PY - 2017
Y1 - 2017
N2 - Lanthanide-doped upconversion nanocrystals (UCNCs) have recently become an attractive nonlinear fluorescence material for use in bioimaging because of their tunable spectral characteristics and exceptional photostability. Plasmonic materials are often introduced into the vicinity of UCNCs to increase their emission intensity by means of enlarging the absorption cross-section and accelerating the radiative decay rate. Moreover, plasmonic nanostructures (e.g., gold nanorods, GNRs) can also influence the polarization state of the UC fluorescence-an effect that is of fundamental importance for fluorescence polarization-based imaging methods yet has not been discussed previously. To study this effect, we synthesized GNR@SiO2@CaF2:Yb3+, Er3+ hybrid core-shell-satellite nanostructures with precise control over the thickness of the SiO2 shell. We evaluated the shell thicknessdependent plasmonic enhancement of the emission intensity in ensemble and studied the plasmonic modulation of the emission polarization at the single-particle level. The hybrid plasmonic UC nanostructures with an optimal shell thickness exhibit an improved bioimaging performance compared with bare UCNCs, and we observed a polarized nature of the light at both UC emission bands, which stems from the relationship between the excitation polarization and GNR orientation. We used electrodynamic simulations combined with Förster resonance energy transfer theory to fully explain the observed effect. Our results provide extensive insights into how the coherent interaction between the emission dipoles of UCNCs and the plasmonic dipoles of the GNR determines the emission polarization state in various situations and thus open the way to the accurate control of the UC emission anisotropy for a wide range of bioimaging and biosensing applications.
AB - Lanthanide-doped upconversion nanocrystals (UCNCs) have recently become an attractive nonlinear fluorescence material for use in bioimaging because of their tunable spectral characteristics and exceptional photostability. Plasmonic materials are often introduced into the vicinity of UCNCs to increase their emission intensity by means of enlarging the absorption cross-section and accelerating the radiative decay rate. Moreover, plasmonic nanostructures (e.g., gold nanorods, GNRs) can also influence the polarization state of the UC fluorescence-an effect that is of fundamental importance for fluorescence polarization-based imaging methods yet has not been discussed previously. To study this effect, we synthesized GNR@SiO2@CaF2:Yb3+, Er3+ hybrid core-shell-satellite nanostructures with precise control over the thickness of the SiO2 shell. We evaluated the shell thicknessdependent plasmonic enhancement of the emission intensity in ensemble and studied the plasmonic modulation of the emission polarization at the single-particle level. The hybrid plasmonic UC nanostructures with an optimal shell thickness exhibit an improved bioimaging performance compared with bare UCNCs, and we observed a polarized nature of the light at both UC emission bands, which stems from the relationship between the excitation polarization and GNR orientation. We used electrodynamic simulations combined with Förster resonance energy transfer theory to fully explain the observed effect. Our results provide extensive insights into how the coherent interaction between the emission dipoles of UCNCs and the plasmonic dipoles of the GNR determines the emission polarization state in various situations and thus open the way to the accurate control of the UC emission anisotropy for a wide range of bioimaging and biosensing applications.
KW - Förster resonance energy transfer
KW - Gold nanorods
KW - Lanthanide-doped upconversion nanocrystals
KW - Plasmon-enhanced nonlinear fluorescence
KW - Polarization modulation
UR - http://www.scopus.com/inward/record.url?scp=85028939959&partnerID=8YFLogxK
U2 - 10.1038/lsa.2016.217
DO - 10.1038/lsa.2016.217
M3 - Article
AN - SCOPUS:85028939959
VL - 6
JO - Light: Science and Applications
JF - Light: Science and Applications
SN - 2095-5545
IS - 5
M1 - e16217
ER -