Oxygen plasma treatment is commonly used to sterilize gold nanoparticles by removing chemical contaminants from their surface while simultaneously inducing surface activation and functionalization of nanoparticles for biological, electrocatalytic, or electrochemical studies. In this study, we investigate the influence of oxygen plasma treatment on structural and localized surface plasmon resonance (LSPR) spectral changes of anisotropic gold nanorods (AuNRs) immobilized on an indium tin oxide (ITO) glass substrate. Unlike AuNRs deposited on a glass slide, no noticeable structural change or deformation of AuNRs on ITO was observed while increasing the oxygen plasma treatment time. This result indicates that ITO provides structural stability to AuNRs immobilized on its surface. Additionally, single-particle scattering spectra of AuNRs showed the broadening of LSPR linewidth within 60 s of oxygen plasma treatment as a result of the plasmon energy loss contributed from plasmon damping to ITO due to the removal of capping material from the AuNR surface. Nevertheless, an increase in the surface charge on the AuNR surface was observed by narrowing the LSPR linewidth after 180 s of plasma treatment. The electrochemical study of AuNRs immobilized on ITO electrodes revealed the surface activation and functionalization of AuNRs by increasing plasma treatment. Hence, in this study, a significant understanding of oxygen plasma treatment on AuNRs immobilized on ITO surfaces is provided.

1.
K. A.
Willets
and
R. P.
Van Duyne
, “
Localized surface plasmon resonance spectroscopy and sensing
,”
Annu. Rev. Phys. Chem.
58
,
267
297
(
2007
).
2.
M.
Hu
,
C.
Novo
,
A.
Funston
,
H.
Wang
,
H.
Staleva
,
S.
Zou
,
P.
Mulvaney
,
Y.
Xia
, and
G. V.
Hartland
, “
Dark-field microscopy studies of single metal nanoparticles: Understanding the factors that influence the linewidth of the localized surface plasmon resonance
,”
J. Mater. Chem.
18
,
1949
1960
(
2008
).
3.
Y.
Zhang
,
S.
He
,
W.
Guo
,
Y.
Hu
,
J.
Huang
,
J. R.
Mulcahy
, and
W. D.
Wei
, “
Surface-plasmon-driven hot electron photochemistry
,”
Chem. Rev.
118
,
2927
2954
(
2018
).
4.
M.
Pita
,
M.
Krämer
,
J.
Zhou
,
A.
Poghossian
,
M. J.
Schöning
,
V. M.
Fernández
, and
E.
Katz
, “
Optoelectronic properties of nanostructured ensembles controlled by biomolecular logic systems
,”
ACS Nano
10
,
2160
2166
(
2008
).
5.
Y. A.
Attia
,
D.
Buceta
,
F. G.
Requejo
,
L. J.
Giovanetti
, and
M. A.
López-Quintela
, “
Photostability of gold nanoparticles with different shapes: The role of Ag clusters
,”
Nanoscale
7
,
11273
11279
(
2015
).
6.
S. Y.
Lee
,
P. V.
Tsalu
,
G. W.
Kim
,
M. J.
Seo
,
J. W.
Hong
, and
J. W.
Ha
, “
Tuning chemical interface damping: Interfacial electronic effects of adsorbate molecules and sharp tips of single gold bipyramids
,”
Nano Lett.
19
,
2568
2574
(
2019
).
7.
K. R.
Ryu
,
G. W.
Kim
, and
J. W.
Ha
, “
Localized surface plasmon resonance inflection points for improved detection of chemisorption of 1-alkanethiols under total internal reflection scattering microscopy
,”
Sci. Rep.
11
,
12902
(
2021
).
8.
K. R.
Ryu
and
J. W.
Ha
, “
Enhanced detection sensitivity of the chemisorption of pyridine and biotinylated proteins at localized surface plasmon resonance inflection points in single gold nanorods
,”
Analyst
146
,
3543
3548
(
2021
).
9.
N.
Khlebtsov
and
L.
Dykman
, “
Biodistribution and toxicity of engineered gold nanoparticles: A review of in vitro and in vivo studies
,”
Chem. Soc. Rev.
40
,
1647
1671
(
2011
).
10.
T.
Sannomiya
,
H.
Dermutz
,
C.
Hafner
,
J.
Vörös
, and
A. B.
Dahlin
, “
Electrochemistry on a localized surface plasmon resonance sensor
,”
Langmuir
26
,
7619
7626
(
2010
).
11.
R.
MacKenzie
,
C.
Fraschina
,
B.
Dielacher
,
T.
Sannomiya
,
A. B.
Dahlin
, and
J.
Vörös
, “
Simultaneous electrical and plasmonic monitoring of potential induced ion adsorption on metal nanowire arrays
,”
Nanoscale
5
,
4966
4975
(
2013
).
12.
C. P.
Byers
,
B. S.
Hoener
,
W.-S.
Chang
,
S.
Link
, and
C. F.
Landes
, “
Single-particle plasmon voltammetry (spPV) for detecting anion adsorption
,”
Nano Lett.
16
,
2314
2321
(
2016
).
13.
T. F.
Jaramillo
,
S.-H.
Baeck
,
B. R.
Cuenya
, and
E. W.
McFarland
, “
Catalytic activity of supported Au nanoparticles deposited from block copolymer micelles
,”
J. Am. Chem. Soc.
125
,
7148
7149
(
2003
).
14.
X.
Wang
,
X.
Zhu
,
H.
Shi
,
Y.
Chen
,
Z.
Chen
,
Y.
Zeng
,
Z.
Tang
, and
H.
Duan
, “
Three-dimensional-stacked gold nanoparticles with sub-5 nm gaps on vertically aligned TiO2 nanosheets for surface-enhanced Raman scattering detection down to 10 fM scale
,”
ACS Appl. Mater. Interfaces
10
,
35607
35614
(
2018
).
15.
B. S.
Hoener
,
C. P.
Byers
,
T. S.
Heiderscheit
,
A. S.
De Silva Indrasekara
,
A.
Hoggard
,
W.-S.
Chang
,
S.
Link
, and
C. F.
Landes
, “
Spectroelectrochemistry of halide anion adsorption and dissolution of single gold nanorods
,”
J. Phys. Chem. C
120
,
20604
20612
(
2016
).
16.
B. S.
Hoener
,
H.
Zhang
,
T. S.
Heiderscheit
,
S. R.
Kirchner
,
A. S.
De Silva Indrasekara
,
R.
Baiyasi
,
Y.
Cai
,
P.
Nordlander
,
S.
Link
,
C. F.
Landes
, and
W.-S.
Chang
, “
Spectral response of plasmonic gold nanoparticles to capacitive charging: Morphology effects
,”
J. Phys. Chem. Lett.
8
,
2681
2688
(
2017
).
17.
S.
Chen
,
R. S.
Ingram
,
M. J.
Hostetler
,
J. J.
Pietron
,
R. W.
Murray
,
T. G.
Schaaff
,
J. T.
Khoury
,
M. M.
Alvarez
, and
R. L.
Whetten
, “
Gold nanoelectrodes of varied size: Transition to molecule-like charging
,”
Science
280
,
2098
2101
(
1998
).
18.
C.
Novo
,
A. M.
Funston
,
A. K.
Gooding
, and
P.
Mulvaney
, “
Electrochemical charging of single gold nanorods
,”
J. Am. Chem. Soc.
131
,
14664
14666
(
2009
).
19.
C. J.
Murphy
,
T. K.
Sau
,
A. M.
Gole
,
C. J.
Orendorff
,
J.
Gao
,
L.
Gou
,
S. E.
Hunyadi
, and
T.
Li
, “
Anisotropic metal nanoparticles: Synthesis, assembly, and optical applications
,”
J. Phys. Chem. B
109
,
13857
13870
(
2005
).
20.
Q.
Zhang
,
L.
Han
,
H.
Jing
,
D. A.
Blom
,
Y.
Lin
,
H. L.
Xin
, and
H.
Wang
, “
Facet control of gold nanorods
,”
ACS Nano
10
,
2960
2974
(
2016
).
21.
J. S.
DuChene
,
W.
Niu
,
J. M.
Abendroth
,
Q.
Sun
,
W.
Zhao
,
F.
Huo
, and
W. D.
Wei
, “
Halide anions as shape-directing agents for obtaining high-quality anisotropic gold nanostructures
,”
Chem. Mater.
25
,
1392
1399
(
2013
).
22.
G. W.
Kim
and
J. W.
Ha
, “
Single-particle study: Effects of oxygen plasma treatment on structural and spectral changes of anisotropic gold nanorods
,”
Phys. Chem. Chem. Phys.
22
,
11767
11770
(
2020
).
23.
J.
Lee
and
J. W.
Ha
, “
Influence of oxygen plasma treatment on structural and spectral changes in silica-coated gold nanorods studied using total internal reflection microscopy and spectroscopy
,”
Analyst
146
,
4125
4129
(
2021
).
24.
L.
Di
,
J.
Zhang
,
X.
Zhang
,
H.
Wang
,
H.
Li
,
Y.
Li
, and
D.
Bu
, “
Cold plasma treatment of catalytic materials: A review
,”
J. Phys. D: Appl. Phys.
54
,
333001
(
2021
).
25.
Z.
Wang
,
Y.
Zhang
,
E. C.
Neyts
,
X.
Cao
,
X.
Zhang
,
B. W.-L.
Jang
, and
C.-j.
Liu
, “
Catalyst preparation with plasmas: How does it work?
,”
ACS Catal.
8
,
2093
2110
(
2018
).
26.
L.
Di
,
J.
Zhang
, and
X.
Zhang
, “
A review on the recent progress, challenges, and perspectives of atmospheric-pressure cold plasma for preparation of supported metal catalysts
,”
Plasma Processes Polym.
15
,
1700234
(
2018
).
27.
K.
Winkler
,
T.
Wojciechowski
,
M.
Liszewska
,
E.
Górecka
, and
M.
Fiałkowski
, “
Morphological changes of gold nanoparticles due to adsorption onto silicon substrate and oxygen plasma treatment
,”
RSC Adv.
4
,
12729
12736
(
2014
).
28.
O.
Shin-ya
,
H.
Junhui
, and
K.
Toyoki
, “
Fabrication of gold nanosheet and nanowire by oxygen plasma induced fusion of densely arrayed nanoparticles
,”
Chem. Lett.
35
,
214
215
(
2006
).
29.
J.
Gun
,
D.
Rizkov
,
O.
Lev
,
M. H.
Abouzar
,
A.
Poghossian
, and
M. J.
Schöning
, “
Oxygen plasma-treated gold nanoparticle-based field-effect devices as transducer structures for bio-chemical sensing
,”
Microchim. Acta
164
,
395
404
(
2009
).
30.
Y.
Duan
,
S.
Rani
,
J. T.
Newberg
, and
A. V.
Teplyakov
, “
Investigation of the influence of oxygen plasma on supported silver nanoparticles
,”
J. Vac. Sci. Technol. A
36
,
01B101
(
2018
).
31.
A.
Sonawane
,
M. A.
Mujawar
, and
S.
Bhansali
, “
Effects of cold atmospheric plasma treatment on the morphological and optical properties of plasmonic silver nanoparticles
,”
Nanotechnology
31
,
365706
(
2020
).
32.
K.
Sugiyama
,
H.
Ishii
,
Y.
Ouchi
, and
K.
Seki
, “
Dependence of indium–tin–oxide work function on surface cleaning method as studied by ultraviolet and x-ray photoemission spectroscopies
,”
J. Appl. Phys.
87
,
295
298
(
2000
).
33.
Y. S.
Park
,
E.
Kim
,
B.
Hong
, and
J.
Lee
, “
Characteristics of ITO films with oxygen plasma treatment for thin film solar cell applications
,”
Mater. Res. Bull.
48
,
5115
5120
(
2013
).
34.
Y.
Hashimoto
and
M.
Hamagaki
, “
Effect of oxygen plasma treatment of indium tin oxide for organic solar cell
,”
Electr. Eng. Jpn.
154
,
1
7
(
2006
).
35.
C.
Aliaga
,
J. Y.
Park
,
Y.
Yamada
,
H. S.
Lee
,
C.-K.
Tsung
,
P.
Yang
, and
G. A.
Somorjai
, “
Sum frequency generation and catalytic reaction studies of the removal of organic capping agents from Pt nanoparticles by UV–ozone treatment
,”
J. Phys. Chem. C
113
,
6150
6155
(
2009
).
36.
Y.
Guo
,
X.
Zhu
,
N.
Li
,
J.
Yang
,
Z.
Yang
,
J.
Wang
, and
B.
Yang
, “
Molecular sensitivities of substrate-supported gold nanocrystals
,”
J. Phys. Chem. C
123
,
7336
7346
(
2019
).

Supplementary Material

You do not currently have access to this content.