New type of highly absorbing core-shell AZO/Au (aluminum doped zinc oxide/gold) and GZO/Au (gallium doped zinc oxide/gold) nanoparticles have been proposed for hyperthermia of malignant cells purposes. Comparative studies of pulsed laser hyperthermia were performed for Au nanoshells with AZO core and traditional SiO 2 (quartz) core. We show that under equal conditions, the hyperthermia efficiency in the case of AZO increases by several orders of magnitude compared to SiO 2 due to low heat capacity of AZO. Similar results have been obtained for GZO core which has same heat capacity. Calculations for pico-, nano-and sub-microsecond pulses demonstrate that reduced pulse duration results in strong spatial localization of overheated areas around nanoparticles, which ensures the absence of negative effects to the normal tissue. Moreover, we propose new alternative way for the optimization of hyperthermia efficiency: instead of maximizing the absorption of nanoparticles, we enhance the thermal damage effect on the membrane of malignant cell. This strategy allows to find the parameters of nanoparticle and the incident radiation for the most effective therapy.
Collective lattice resonances in regular arrays of plasmonic nanoparticles have attracted much attention due to a large number of applications in optics and photonics. Most of the research in this field is concentrated on the electric dipolar lattice resonances, leaving higher-order multipolar lattice resonances in plasmonic nanostructures relatively unexplored. Just a few works report exceptionally high-Q multipolar lattice resonances in plasmonic arrays, but only with infinite extent (i.e., perfectly periodic). In this work, we comprehensively study multipolar collective lattice resonances both in finite and in infinite arrays of Au and Al plasmonic nanoparticles using a rigorous theoretical treatment. It is shown that multipolar lattice resonances in the relatively large (up to 6400 nanoparticles) finite arrays exhibit broader full width at half maximum (FWHM) compared to similar resonances in the infinite arrays. We argue that our results are of particular importance for the practical implementation of multipolar lattice resonances in different photonics applications.
We numerically investigate the conditions for the laser-induced formation of nanobubbles in aqueous medium around plasmonic nanoparticles bound to the malignant cell membranes that is considered as the method of their irreversible damage. We proposed employing the versatile and accessible simulation software as a research tool based on the finite volume method underlying the ANSYS Fluent package and supplemented with our user-defined functions that adapt it to solution of the stated problems. This adaptation allows to verify the model using experimental data for the same conditions. We determined the conditions for the pressure growth on the cell membrane at the initial moment of bubble formation significantly exceeding the threshold of irreversible damage. The model can be used for investigation of hydrodynamic effects accompanying irradiation of plasmonic nanoparticles using both different types of pulsed lasers and ideally absorbing nanoparticles with resonance in the hemoglobin spectral transparency range, as well as to uncover previously unknown effects. They include the conditions for localization of a damaging factor non-affecting the normal cells, the conditions for generation of ultrahigh pressure pulse that enables to damage the cell membrane and precedes formation of a thin vapor shell around nanoparticles, which, unlike large bubbles, requires registration using highly sensitive experimental measurements. An extensive overview of key publications summarizing the state-of-art in this area is presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.