TY - JOUR
T1 - Plasmon-Resonant Gold Nanostars with Variable Size as Contrast Agents for Imaging Applications
AU - Bibikova, Olga
AU - Popov, Alexey
AU - Bykov, Alexander
AU - Fales, Andrew
AU - Yuan, Hsiangkuo
AU - Skovorodkin, Ilya
AU - Kinnunen, Matti
AU - Vainio, Seppo
AU - Vo-Dinh, Tuan
AU - Tuchin, Valery V.
AU - Meglinski, Igor
PY - 2016/5/1
Y1 - 2016/5/1
N2 - Plasmon-resonant nanostars (NSts) have recently found applications in biophotonics due to their unique optical and chemical characteristics, showing comparable or superior properties than other anisotropic plasmon-resonant nanoparticles. In this paper, we synthesized gold NSts by the seed-mediated surfactant-free method. By varying the diameters and amount of spherical seeds we tuned the final NSts tip-to-tip sizes to 50, 82, 100, and 120 nm ensuring the plasmon-resonant peak location between 710 and 830 nm, and the scattering/absorption ratio at the plasmon-resonant wavelengths being 0.12, 0.25, 0.30, 0.35 correspondingly. We investigated the application of the NSts as contrast agents for imaging techniques operating at visible and infrared wavelengths: optical coherence tomography (OCT) and Doppler OCT with the spectrum centered at 930-nm wavelength, as well as for conventional confocal laser scanning microscopy (CLSM) working at 633 nm. The most intense OCT signal was registered from the largest NSts, in correspondence with spectroscopy measurements at 930-nm wavelength. For imaging of nanoparticles incubated with living cells, we applied CLSM in combined scattering and transmission modes, and observed localization of the NSts on the cell surface. Due to the highest scattering at the CLSM operating wavelength, the strongest signal was obtained from the 82-nm particles; the lowest intensity of the CLSM backscattered signal was detected from the cells labeled with the smallest NSts. Thus, by tuning the initial concentration of seeds, it is possible to adjust the size (and scattering properties) of the nanostars to the operating wavelength of the optical device to achieve the best performance.
AB - Plasmon-resonant nanostars (NSts) have recently found applications in biophotonics due to their unique optical and chemical characteristics, showing comparable or superior properties than other anisotropic plasmon-resonant nanoparticles. In this paper, we synthesized gold NSts by the seed-mediated surfactant-free method. By varying the diameters and amount of spherical seeds we tuned the final NSts tip-to-tip sizes to 50, 82, 100, and 120 nm ensuring the plasmon-resonant peak location between 710 and 830 nm, and the scattering/absorption ratio at the plasmon-resonant wavelengths being 0.12, 0.25, 0.30, 0.35 correspondingly. We investigated the application of the NSts as contrast agents for imaging techniques operating at visible and infrared wavelengths: optical coherence tomography (OCT) and Doppler OCT with the spectrum centered at 930-nm wavelength, as well as for conventional confocal laser scanning microscopy (CLSM) working at 633 nm. The most intense OCT signal was registered from the largest NSts, in correspondence with spectroscopy measurements at 930-nm wavelength. For imaging of nanoparticles incubated with living cells, we applied CLSM in combined scattering and transmission modes, and observed localization of the NSts on the cell surface. Due to the highest scattering at the CLSM operating wavelength, the strongest signal was obtained from the 82-nm particles; the lowest intensity of the CLSM backscattered signal was detected from the cells labeled with the smallest NSts. Thus, by tuning the initial concentration of seeds, it is possible to adjust the size (and scattering properties) of the nanostars to the operating wavelength of the optical device to achieve the best performance.
KW - cellular biophysics
KW - confocal laser scanning microscopy
KW - gold nanostars
KW - optical coherence tomography
KW - plasmon-resonant nanoparticles
KW - scattering
KW - Spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84968901995&partnerID=8YFLogxK
UR - https://ieeexplore.ieee.org/document/7400932
U2 - 10.1109/JSTQE.2016.2526602
DO - 10.1109/JSTQE.2016.2526602
M3 - Article
AN - SCOPUS:84968901995
SN - 0792-1233
VL - 22
JO - IEEE Journal of Selected Topics in Quantum Electronics
JF - IEEE Journal of Selected Topics in Quantum Electronics
IS - 3
M1 - 7400932
ER -