2023, Тимошенко, В. Ю., Харин, А. Ю., Базыленко, Т. Ю., Еремина, А. С., Карамов, Э. В., Ларичев, В. Ф., Корнилаева, Г. В., Еремина, Анна Сергеевна, Тимошенко, Виктор Юрьевич, Базыленко, Татьяна Юрьевна

Изобретение относится к способу получения наночастиц для инактивации коронавирусной инфекции. Предложенный способ получения водных суспензий кремниевых наночастиц включает травление пластин кристаллического кремния дырочного типа проводимости с ориентацией поверхности (100) с удельным сопротивлением от 1 до 50 мОм*см в растворе плавиковой кислоты с объемной концентрацией 40-50% и этилового спирта в соотношении от 1:1 до 1:5 по объему соответственно в течение промежутка времени от 10 до 60 мин с плотностью тока от 20 до 60 мА/см2, с дальнейшим механическим измельчением полученных мезопористых слоев толщиной от 10 до 100 мкм, диаметром пор от 2 до 10 нм и пористостью от 50 до 80%. Полученные пленки мезопористого кремния отделяют от подложки, промывают в дистиллированной воде, высушивают на воздухе при комнатной температуре и подвергают механическому измельчению в дистиллированной воде посредством помола в шаровой планетарной мельнице до получения водной суспензии кремниевых наночастиц. Далее полученную суспензию подвергают центрифугированию при центробежных ускорениях от 1000 до 2000 ускорений свободного падения в течение промежутка времени от 10 до 20 мин для осаждения крупных наночастиц кремния, удаляемых затем из суспензии. В дальнейшем используется надосадочная фракция суспензии наночастиц, которая подвергается диализу в течение 24 часов в диализных мешках с размером пор 40 кДа для очистки от самых мелких наночастиц и растворенных веществ. В результате образуется стабильная водная суспензия кремниевых наночастиц со средними поперечными размерами порядка 100 нм, представляющих собой агрегаты нанокристаллов кремния с размерами 10-20 нм, обладающих высокой стабильностью в течение нескольких недель, высокой эффективностью инактивации коронавируса и низкой цитотоксичностью. 2 ил., 1 табл., 2 пр.

2020, Sharonova, N. V., Svirshchevskaya, E. V., Popov, A. A., Karpov, N. V., Tikhonovsky, G. V., Zakharkiv, A. Y., Timoshenko, V. Y., Klimentov, S. M., Oleinikov, V. A., Попов, Антон Александрович, Тихоновский, Глеб Валерьевич, Захаркив, Анастасия Юрьевна, Тимошенко, Виктор Юрьевич, Климентов, Сергей Михайлович, Олейников, Владимир Александрович

Silicon and silicon-based nanoparticles (SiNP) attract scientific attention due to the biocompatibility and assimilation of silicon by body tissues. Iron-doped SiNP (SiFeNP) allow the use of ferromagnetic properties of iron for NP detection and the possibility of therapeutic application of SiFeNP. The purpose of this work was to analyze the interaction of SiFeNP with epithelial cells (EC) COLO357 and SW620 and human peripheral blood lymphocytes (PBL). SiFeNP were obtained by laser ablation and divided into the NP1 and NP2 fractions of 100 and 150 nm size, respectively. Cytotoxicity, apoptosis induction, reactive oxygen species (ROS) production, and lysosome metabolism were analyzed using in vitro methods. EC were found to efficiently incytosed both types of NPs, which resulted in the increase in the granularity of cells. NP did not cause apoptosis or EC necrosis, but accumulated in lysosomes, which led to a decrease in the membrane potential of lysosomes. In turn, a decrease in the level of EC metabolism led to a gradual (24 h) increase in ROS production by 10-15%. NP1 caused more ROS than NP2, and accumulated more in the EC, which may be the result of a difference in the particle size. SiFeNP did not interact with PBL. Thus, the total cytotoxicity of SiFeNP did not exceed 20%, which is associated with a decrease in lysosome metabolism and insignificant ROS production.

2019, Rodichkina, S. P., Nychyporuk, T., Pavlikov, A. V., Lysenko, V., Timoshenko, V., Тимошенко, Виктор Юрьевич

© 2019 John Wiley & Sons, Ltd.Raman spectroscopy is used to probe free charge carriers in layers of silicon nanowires (SiNWs) formed by metal-assisted chemical etching of crystalline silicon (c-Si) wafers followed by additional doping with boron. One-phonon Raman spectra of the boron-doped SiNWs are strongly modified due to the Fano effect that allowed us to determine the free carrier concentration in the nanowires in the range from 1019 to 1020 cm−3, depending on the doping conditions. The micro-Raman mapping was used to determine the depth profile of charge carrier density along nanowires, which decreases toward the SiNWs/c-Si interface. The obtained results are discussed in view of possible applications of the Raman spectroscopy for express-diagnostics of doped Si nanostructures for photonics and thermoelectric applications.

2019, Rogov, A., Ryabchikov, Y. V., Geloen, A., Tishchenko, I., Kharin, A. Y., Lysenko, V., Zavestovskaya, I. N., Kabashin, A. V., Timoshenko, V. Y., Завестовская, Ирина Николаевна, Кабашин, Андрей Викторович, Тимошенко, Виктор Юрьевич

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Presenting a safe alternative to conventional compound quantum dots and other functional nanostructures, nanosilicon can offer a series of breakthrough hyperthermia-based therapies under near-infrared, radiofrequency, ultrasound, etc., excitation, but the size range to sensitize these therapies is typically too large (>10 nm) to enable efficient imaging functionality based on photoluminescence properties of quantum-confined excitonic states. Here, it is shown that large Si nanoparticles (NPs) are capable of providing two-photon excited luminescence (TPEL) and second harmonic generation (SHG) responses, much exceeding that of smaller Si NPs, which promises their use as probes for bi-modal nonlinear optical bioimaging. It is finally demonstrated that the combination of TPEL and SHG channels makes possible efficient tracing of both separated Si NPs and their aggregations in different cell compartments, while the resolution of such an approach is enough to obtain 3D images. The obtained bi-modal contrast provides lacking imaging functionality for large Si NPs and promises the development of novel cancer theranostic modalities on their basis.

2020, Oleshchenko, V. A., Bezotosnyi, V. V., Timoshenko, V. Y., Тимошенко, Виктор Юрьевич

3D simulation of the distribution of thermal fields in aqueous suspensions of silicon nanoparticles upon irradiation by a high-power 808-nm laser diode operating in cw and quasi-cw repetitively pulsed regimes is performed. It is shown that irradiation by a repetitively pulsed laser with a peak power of 10 W and a pulse duration of 300 ms can form a region with a maximum temperature exceeding 42 degrees C, which is promising for application in cancer photohyperthermia for local heating of biotissues at a given depth.

2020, Povarnitsyn, M. E., Shcheblanov, N. S., Ivanov, D. S., Timoshenko, V. Y., Klimentov, S. M., Тимошенко, Виктор Юрьевич, Климентов, Сергей Михайлович

We report a classical molecular-dynamics simulation of models of silicon nanoparticles and bulk sili-con, in both the crystalline and the amorphous phase, to investigate their vibrational properties. By using a dynamical-matrix approach and a bond-polarizability model, together with a Raman-decomposition approach [Phys. Rev. B 100, 134309 (2019)], we present a comprehensive analysis of the vibrational spec-tra. In particular, the dependence of the high-frequency range of the Raman spectra on the nanoparticle size is studied. The results are in good agreement with Raman measurements on crystalline nanoparticles and explain the role of the nanoparticle surface, which is responsible for a shift in the Raman spectrum dependent on the particle size. In the low-frequency range, our Raman calculations reproduce well the Lamb-mode signatures, which obey the selection rules deduced by Duval [Phys. Rev. B 46, 5795 (1992)]. As a result of systematic Raman modeling, we confirm the scaling of the main signatures (ascribed to the Lamb modes with l = 0, 2) with respect to the nanoparticle size. By using the Raman-decomposition approach, we demonstrate that only a thin surface layer several angstroms in thickness contributes to the low-frequency Raman signature regardless of the nanoparticle size in the case of both the amorphous and the crystalline phase. Finally, we study the role of the coordination number of the atoms in the surface layer of a nanoparticle in order to explain the difference between the crystalline and amorphous vibrational spectra. The approach developed provides knowledge necessary for the correct interpretation of Raman spectra of nanoparticles, which opens up the possibility of quantitative control of surface-induced effects that may be relevant to various applications.

2019, Efimova, A. I., Lipkova, E. A., Gonchar, K. A., Eliseev, A. A., Timoshenko, V. Yu., Тимошенко, Виктор Юрьевич

Free charge carrier concentration in arrays of silicon nanowires (SiNWs) with cross-sectional size of the order of 100 nm was quantitatively studied by means of the infrared spectroscopy in an attenuated total reflection mode. SiNWs were formed on lightly-doped p-type crystalline silicon substrates by metal-assisted chemical etching followed by additional doping through thermo-activated diffusion of boron at 900-1000 degrees C. The latter process was found to increase the concentration of free holes in SiNWs up to (1-3) x 10(19) cm(-3). Potential applications of highly doped SiNWs in thermoelectric energy converters and infrared plasmonic devices are discussed.

2020, Rodichkina, S. P., Nychyporuk, T., Pavlikov, A. V., Lysenko, V., Timoshenko, V. Y., Тимошенко, Виктор Юрьевич

The impact of free charge carriers in arrays of silicon nanowires (SiNWs) of p- and n-type conductivities on their optical properties is probed by means of the infrared spectroscopy in attenuated total reflectance mode (IR-ATR) and Raman scattering. SiNWs are fabricated by metal-assisted chemical etching of low-doped p-type crystalline silicon (c-Si) wafers followed by thermodiffusional doping with p- and n-type impurities. The free charge carrier concentration in SiNWs is determined from their ATR spectra fitted using a model of the anisotropic effective medium with free charge carriers. The obtained data on the free charge carrier concentrations in the range of 10(19)-10(20) cm(-3) are compared with the corresponding values obtained from the Raman spectra, which are analyzed by considering the Fano effect in SiNWs, and the results of both methods are used to evaluate the electrical properties of SiNWs. The proposed optical methods to probe the electrical properties of SiNWs are discussed in view of possible applications in nanoelectronics and thermoelectric devices.

2019, Perepukhov, A. M., Zvereva, E. A., Koshelev, A. V., Maximychev, A. V., Kargina, Y. V., Kharin, A. Y., Zinovyev, S. V., Alykova, A. F., Pirogov, Y. A., Timoshenko, V. Y., Тимошенко, Виктор Юрьевич

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Silicon (Si) nanoparticles (NPs) with small (10 −3 –10 −1 at%) content of iron oxide (Fe 2 O 3 ) are prepared by plasma-assisted ablative synthesis. Powders of the prepared Si-iron oxide (SIO) NPs are investigated by means of the transmission electron microscopy, Raman spectroscopy, electron paramagnetic resonance, and magnetic susceptibility measurements. Aqueous suspensions of the NPs are studied by using dynamic light scattering and nuclear magnetic resonance technique. The longitudinal and transverse relaxation times of protons in aqueous suspensions of the NPs are found to be dependent on the iron content. The stronger decrease of the proton relaxation is detected for the samples with higher iron content. Magnetic resonance imaging (MRI) experiments show that SIO NPs have properties of the MRI contrast agent and it is confirmed by in vivo experiments with cancer tumor. Aqueous suspensions of SIO NPs are explored as sensitizers of electromagnetic radio frequency hyperthermia and the highest heating rate is observed for the NPs with smaller hydrodynamic size (≈50 nm). The obtained results indicate possible ways for applications of SIO NPs in the MRI diagnostics and mild therapy of cancer.

2019, Zhanabaev, Z. Zh., Grevtseva, T. Yu., Gonchar, K. A., Yermukhamed, D., Mussabek, G., Timoshenko, V. Yu., Тимошенко, Виктор Юрьевич

© 2019 CEUR-WS. All rights reserved.This work has been done to identify quantitative criteria the degree of order and chaos morphology of porous layers consisting of silicon nanowire arrays. In order to fulfill the work, a method of using metal-assisted chemical etching has been utilized to produce nanowires. There has been done a work of digital processing of porous film images which were extracted by scanning electron microscope. Informational-entropic and Fourier analysis have been applied to quantitatively describe the degree of order and chaos in nanostructure distribution in the layers. Self-similarity of the layer morphology has been quantitatively described via its fractal dimensions by correlation method. The applied approach for image processing allows us to distinguish the morphological features of as-called "black" (more ordered) and "white" (less ordered) silicon layers, which are characterized by minimal and maximal optical reflection, respectively. From all of the methods of digital techniques that we have used the method for determining the conditional information of a chaotic set was proved to be the most informative.