CC BY
6B-O-4
The 30th International Conference on Advanced Laser Technologies
ALT'23
Gold nanostars with tunable optical properties for biomedical
applications
V.A. Khanadeev1, A.V. Simonenko1, N.G. Khlebtsov12
1-Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian
Academy of Sciences (IBPPMRAS), 13 Prospect Entuziastov, Saratov 410049, Russia 2- Saratov State University of Genetics, Biotechnology and Engineering Named after N. I. Vavilov, 1 Teatralnaya pl.,
Saratov 410012, Russia 3- Saratov State University, 83 Ulitsa Astrakhanskaya, Saratov 410012, Russia
Gold nanoparticles are widely used in laser-based biomedical applications due to the presence of localized surface plasmon resonance. Effective use in applications such as photothermal therapy, photoacoustic imaging, surface-enhanced Raman spectroscopy, etc. often requires spectral tuning of the plasmon resonance of nanoparticles to a given wavelength, usually coinciding with the wavelength of laser irradiation. In this case, gold nanostars compare favorably with particles of other shapes in that their plasmon resonance can be tuned in a wide wavelength range from 650 to 1900 nm. This range includes the so-called first, second and third biological penetration windows - spectral regions with the maximum depth of light penetration through biological tissues. Another feature of nanostars is sharp spikes on the surface, which can also be effectively used, for example, as "hot" spots for SERS applications.
The purpose of this work was to analyze the available literature data and perform an additional experimental study of the dependence of the morphological and optical properties of gold nanostars on the concentrations of reagents added during synthesis. Using transmission electron microscopy and extinction spectroscopy, we studied nanostars synthesized using two different seed-mediated methods: surfactant-free protocol developed by T. Vo-Dinh group [1] (Fig.la) and Triton-based protocol developed by P. Pallavicini [2] (Fig. 1b). It was found that the main factors affecting the shape and optical properties of nanoparticles are the concentrations of silver nitrate, seeds and hydrochloric acid. The results obtained can be used to create gold nanostars with the necessary morphological and optical parameters for specific applications.
The work was supported by a grant from the Russian Science Foundation No. 23-22-00354, https://rscf.ru/en/proj ect/23-22-00354/.
[1] H. Yuan, C.G. Khoury, H. Hwang, C.M. Wilson, G.A. Grant, T. Vo-Dinh, Gold nanostars: surfactant-free synthesis, 3D modelling, and two-photon photoluminescence imaging, Nanotechnology, vol. 23:075102, (2012).
[2] P. Pallavicini, A. Dona, A. Casu, G. Chirico, M. Collini, G. Dacarro, A. Falqui, C. Milanese, L. Sironi, A. Taglietti, Triton X-100 for three-plasmon gold nanostars with two photothermally active NIR (near IR) and SWIR (short-wavelength IR) channels, Chem. Commun., vol. 49, pp. 6265-6267, (2013).
Fig. 1. TEM images of gold nanostars synthesized according to (a) surfactant-free and (b) triton-based protocols.
