Персона: Гармаш, Александр Александрович
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Инженерно-физический институт биомедицины
Цель ИФИБ и стратегия развития – это подготовка высококвалифицированных кадров на базе передовых исследований и разработок новых перспективных методов и материалов в области инженерно-физической биомедицины. Занятие лидерских позиций в биомедицинских технологиях XXI века и внедрение их в образовательный процесс, что отвечает решению практикоориентированной задачи мирового уровня – диагностике и терапии на клеточном уровне социально-значимых заболеваний человека.
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Александр Александрович
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- ПубликацияОткрытый доступTailoring Photoluminescence from Si-Based Nanocrystals Prepared by Pulsed Laser Ablation in He-N2 Gas Mixtures(2020) Muratov, A. V.; Fronya, A. A.; Antonenko, S. V.; Kharin, A. Y.; Aleshchenko, Y. A.; Derzhavin, S. I.; Karpov, N. V.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Алещенко, Юрий Анатольевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей ВикторовичUsing methods of pulsed laser ablation from a silicon target in helium (He)-nitrogen (N2) gas mixtures maintained at reduced pressures (0.5-5 Torr), we fabricated substrate-supported silicon (Si) nanocrystal-based films exhibiting a strong photoluminescence (PL) emission, which depended on the He/N2 ratio. We show that, in the case of ablation in pure He gas, Si nanocrystals exhibit PL bands centered in the "red - near infrared" (maximum at 760 nm) and "green" (centered at 550 nm) spectral regions, which can be attributed to quantum-confined excitonic states in small Si nanocrystals and to local electronic states in amorphous silicon suboxide (a-SiOx) coating, respectively, while the addition of N2 leads to the generation of an intense "green-yellow" PL band centered at 580 nm. The origin of the latter band is attributed to a radiative recombination in amorphous oxynitride (a-SiNxOy) coating of Si nanocrystals. PL transients of Si nanocrystals with SiOx and a-SiNxOy coatings demonstrate nonexponential decays in the micro- and submicrosecond time scales with rates depending on nitrogen content in the mixture. After milling by ultrasound and dispersing in water, Si nanocrystals can be used as efficient non-toxic markers for bioimaging, while the observed spectral tailoring effect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.
- ПубликацияТолько метаданныеPhotoluminescent Si-based nanocrystals prepared by pulsed laser ablation in low-pressure helium-nitrogen mixtures for biomedical applications(2020) Kharin, A. Y.; Fronya, A. A.; Antonenko, S. V.; Karpov, N. V.; Derzhavin, S. I.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей Викторович© 2020 SPIE.Nanocrystalline silicon (Si) films were synthesized by nanosecond laser ablation of crystalline Si targets in low-pressure helium (He) and nitrogen (N2) gas mixtures. Photoluminescence (PL) spectra of the prepared samples were found to depend on the He/N2 ratio in the gas mixture. The ablation pure He atmosphere allowed us to prepare Si nanocrystals (NCs) exhibiting a PL band in red-near-IR range, while samples prepared in the presence of N2 exhibited a strong PL band with maximum in the green-yellow region. Such a modification of PL properties can be explained by the presence of amorphous Si oxynitride (a-SiNxOy) on the surface of Si-NCs. Structural studies of the prepared samples by means of the scanning electron microscopy revealed different morphology for Si-NCs produced under different gas mixtures. After treating of the films by ultrasound and dispersing in water, Si-NCs can be used as novel biodegradable markers for bioimaging, while the observed spectral tailoring effect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.
- ПубликацияТолько метаданныеMorphology and photoluminescence properties of silicon nanoparticles deposited in helium-nitrogen mixtures maintained at low residual pressures(2021) Fronya, A. A.; Antonenko, S. V.; Derzhavin, S. I.; Karpov, N. V.; Kharin, A. Yu.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Yu.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей ВикторовичWe elaborated a technique of pulsed laser ablation in gas mixtures (He-N2), maintained under residual pressures of 0.5-5 Torr to deposit silicon (Si)-based nanostructured films on a substrate. We show that the deposited films can exhibit strong photoluminescence (PL) emission with the position of peaks depending on the pressure of ambient gas and the ratio of gases in the mixture. Nanostructured films prepared in pure He gas exhibited a strong band in the infrared range (around 760 nm) and a weak band in the green range (550 nm), which were attributed to quantum-confined excitonic states in small Si nanocrystals and radiative transitions via the localized electronic states in silicon suboxide coating, respectively. In contrast, nanostructured films prepared in He-N2 mixtures exhibited more intense “green-yellow” PL band centered at 580 nm, which was attributed to a radiative recombination in amorphous oxynitride (a-SiNxOy) coating of Si nanocrystals. We also present a detailed analysis of morphology of nanostructures Si-based films prepared by laser ablation. Finally, we show that the nanocrystals can be removed from the substrate and milled by ultrasound to form aqueous solutions of colloidal Si nanopartiles. The fabricated Si-based nanocrystals present a promising object for theranostics, combining imaging functionality based on PL emission and a series of therapy functionalities (photo and radiofrequency hyperthermia, photodynamic therapy). © 2021 Institute of Physics Publishing. All rights reserved.
- ПубликацияТолько метаданныеGermanium Nanoparticles Prepared by Laser Ablation in Low Pressure Helium and Nitrogen Atmosphere for Biophotonic Applications(2022) Fronya, A. A.; Antonenko, S. V.; Karpov, N. V.; Pokryshkin, N. S.; Eremina, A. S.; Kharin, A. Y.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Еремина, Анна Сергеевна; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор ЮрьевичDue to particular physico-chemical characteristics and prominent optical properties, nanostructured germanium (Ge) appears as a promising material for biomedical applications, but its use in biological systems has been limited so far due to the difficulty of preparation of Ge nanostructures in a pure, uncontaminated state. Here, we explored the fabrication of Ge nanoparticles (NPs) using methods of pulsed laser ablation in ambient gas (He or He-N2 mixtures) maintained at low residual pressures (1-5 Torr). We show that the ablated material can be deposited on a substrate (silicon wafer in our case) to form a nanostructured thin film, which can then be ground in ethanol by ultrasound to form a stable suspension of Ge NPs. It was found that these formed NPs have a wide size dispersion, with sizes between a few nm and hundreds of nm, while a subsequent centrifugation step renders possible the selection of one or another NP size fraction. Structural characterization of NPs showed that they are composed of aggregations of Ge crystals, covered by an oxide shell. Solutions of the prepared NPs exhibited largely dominating photoluminescence (PL) around 450 nm, attributed to defects in the germanium oxide shell, while a separated fraction of relatively small (5-10 nm) NPs exhibited a red-shifted PL band around 725 nm under 633 nm excitation, which could be attributed to quantum confinement effects. It was also found that the formed NPs exhibit high absorption in the visible and near-IR spectral ranges and can be strongly heated under photoexcitation in the region of relative tissue transparency, which opens access to phototherapy functionality. Combining imaging and therapy functionalities in the biological transparency window, laser-synthesized Ge NPs present a novel promising object for cancer theranostics.
- ПубликацияТолько метаданныеLaser Synthesis of Bismuth Nanoparticles for Multimodal Theranostics of Oncological Diseases(2022) Tikhonowski, G. V.; Popov, A. A.; Kurinnaya, A. A.; Garmash, A. A.; Gromushkina, E. V.; Zavestovskaya, I. N.; Klimentov, S. M.; Klimentov, S.M.; Тихоновский, Глеб Валерьевич; Попов, Антон Александрович; Гармаш, Александр Александрович; Громушкина, Елена Вячеславовна; Климентов, Сергей МихайловичAbstract: The effect of laser radiation parameters on properties of bismuth (Bi) nanoparticles (NPs) produced by pulsed laser ablation in liquids (PLAL) was studied. We demonstrated that the average NPs size increases under the increase of laser radiation energy and the decrease in the distance from the focusing lens to the target surface. The obtained results provide a tool for a controllable synthesis of new functional nanomaterials for biomedical applications. © 2022, Allerton Press, Inc.
- ПубликацияТолько метаданныеStudy of IR Photoheating of Aqueous Solutions of Boron Nanoparticles Synthesized by Pulsed Laser Ablation for Cancer Therapy(2022) Belyaev, I. B.; Zelepukin, I. V.; Pastukhov, A. I.; Shakhov, P. V.; Tikhonowski, G. V.; Popov, A. A.; Zakharkiv, A. Y.; Klimentov, S. M.; Garmash, A. A.; Zavestovskaya, I. N.; Deyev, S. M.; Kabashin, A. V.; Шахов, Павел Владимирович; Тихоновский, Глеб Валерьевич; Попов, Антон Александрович; Захаркив, Анастасия Юрьевна; Климентов, Сергей Михайлович; Гармаш, Александр Александрович; Завестовская, Ирина Николаевна; Деев, Сергей МихайловичAbstract: Photothermal properties of boron (B) nanoparticles (NPs) synthesized by pulsed laser ablation in liquid (PLAL) are studied. It is found that B NPs have high optical extinction coefficient in the near infrared (IR) region, in particular, its value was 0.2 l/(cm g) at a wavelength of 800 nm. It is shown that aqueous suspensions of B NPs can be heated during laser irradiation with a wavelength of 830 nm and a radiation power of 1 W. Here, the temperature increase varied from 6.5 to 36°C under the increase of the particle concentration from 0.04 to 0.8 g/L; while the relevant parameter in the absence of particles was 2°C. B NPs were able to provide a stable photothermal response during several irradiation cycles. The results evidence a high potential of B NPs as sensitizers of photothermal therapy (PTT). © 2022, Allerton Press, Inc.
- ПубликацияТолько метаданныеPulsed laser deposition in He-N2 gaseous mixtures for the synthesis of photoluminescent Si and Ge nanoparticles for bioimaging(2023) Fronya, A. A.; Karpov, N. V.; Antonenko, S. V.; Pokryshkin, N. S.; Eremina, A. S.; Kharin, A.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Еремина, Анна Сергеевна; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович