Distance-Dependent
Plasmon-Enhanced
Fluorescence
of
Upconversion Nanoparticles using Polyelectrolyte Multilayers as
Tunable Spacers
Ai Ling Feng
a,b
, Min Li You
a,b
, Limei Tian c, Srikanth Singamaneni c, Ming Liu d,
Zhenfeng Duan e, Tian Jian Lu b, Feng Xu a,b, Min Lin a,b,e #
a
The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of
Life Science and Technology, Xi'an Jiaotong University, Xi’an 710049, P.R. China
b
Bioinspired Engineering and Biomechanics Center (BEBC), Xi’an Jiaotong University, Xi’an
710049, P.R. China
c
Department of Mechanical Engineering and Materials Science, Institute of Materials Science
and Engineering, Washington University in St. Louis, St Louis, MO 63130, USA
d
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education &
International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, P.R. China
e
Center for Sarcoma and Connective Tissue Oncology, Massachusetts General Hospital, Harvard
Medical School, MA 02114, USA
#
Corresponding author: minlin@mail.xjtu.edu.cn
Figure
S1
nanoparticles.
Size
distribution
histogram
of
as-prepared
upconversion
Figure S2 Representative TEM image of UCNPs-PAA. There were no obvious
change in morphology and size as compared with as-prepared UCNPs in Figure 2.
Figure S3 Energy level diagram illustrating the luminescence mechanism of
NaYF4:Yb,Er upconversion nanoparticles with the excitation of NIR laser.
Figure S4 Size distribution histogram (length, diameter and aspect ratio) of
different AuNRs. (a-c) AuNRs-980; (d-f) AuNRs-915; (g-i) AuNRs-735.
Figure S5 UV-Vis-NIR extinction spectrum of AuNRs-980, AuNRs-915 and
AuNRs-735 in solution.
Figure S6 Simulated results of electric fields surrounding the surface of two
AuNRs at the polymer surface with different relative positions. Electric fields
distribution with side-by-side of two AuNRs with aspect ratios of: (a) 7.6
(AuNRs-980); (c) 6.3 (AuNRs-915); (e) 4.5 (AuNRs-735) and head-to-head of two
AuNRs with aspect ratios of: (b) 7.6 (AuNRs-980); (d) 6.3 (AuNRs-915); (f) 4.5
(AuNRs-735) are shown.
Figure S7 Simulated results of electric fields surrounding the surface of
individual AuNRs at the polymer surface. The graph from AuNRs with different
aspect ratios of: (a) 7.6 (AuNRs-980); (b) 6.3 (AuNRs-915); (c) 4.5 (AuNRs-735) are
shown.
Figure S8 Correlation of different aspect ratios of the AuNRs to the electric field
intensity.
Table S1 LSPR wavelength of AuNRs with different aspect ratios.
LSPR Wavelength
LSPR Wavelength
Nomenclature
Blue-shift (nm)
in Solution (nm)
on Silicon (nm)
AuNRs-980
1075
980
95
AuNRs-915
1010
915
95
AuNRs-735
830
735
95
Table S2 Statistical analysis of size distribution for AuNRs with different aspect
ratios.
AuNRs-980
Parameters
AuNRs-915
AuNRs-735
Length
Diameter
Aspect
Length
Diameter
Aspect
Length
Diameter
Aspect
(nm)
(nm)
Ratio
(nm)
(nm)
Ratio
(nm)
(nm)
Ratio
Mean
105.5
14.1
7.6
86.6
14.0
6.3
64.4
14.7
4.5
Max
196.0
22.5
15.5
124.5
17.9
9.0
85.7
19.8
7.3
Min
62.7
10.3
2.9
64.9
9.0
3.9
40.9
10.2
2.7
SD
20.2
1.7
1.9
10.7
1.5
1.0
7.3
1.8
0.8