ФИАН
Научная деятельность
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Рябчиков Юрий Витальевич канд. физ.-мат. наук
Контакты
Дополнительная информация
ORCID: 0000-0002-6844-1051,
Научные публикации Рябчикова Юрия Витальевича: http://sites.lebedev.ru/yuri/, пароль: yuri
Адреса электронной почты:
yur(at)lebedev.ru
Рябчиков Юрий Витальевич окончил кафедру общей физики и молекулярной электроники физического факультета МГУ по специальности "физика твёрдого тела" в 2003 году. По окончанию обучения продолжил научно-исследовательскую работу на той же кафедре под руководством профессора В.Ю. Тимошенко.
Основным направлением работы являлось изготовление кремниевых наноструктур на основе пористого кремния и исследование влияния молекулярного окружения кремниевых нанокристаллов на их оптические и электронные свойства.
В 2005 году Рябчиков Юрий Витальевич был награжден дипломом 1 степени за доклад "Процесс генерации синглетного кислорода с помощью пористого кремния" на VII Всероссийской молодежной конференции по физике полупроводников и полупроводниковой опто- и наноэлектронике.
В 2007 году защитил диссертацию на соискание ученой степени кандидата физико-математических наук по теме "Влияние молекулярного окружения кремниевых нанокристаллов на их фотолюминесцентные свойства".
В 2008 году прошёл конкурс и выиграл стипендию германского фонда академических обменов (ДААД) для прохождения 10-месячной стажировки в Helmholtz Zentrum Berlin (HZB) в Берлине, где совместно с немецкими коллегами занимался разработкой органических солнечных элементов.
С 2010 года начал работу в Физическом институте РАН им. П.Н. Лебедева, в лаборатории физики дефектов и радиационных явлений в полупроводниках под руководством А.А. Гиппиуса. В настоящий момент, является младшим научным сотрудником Лаборатория физики дефектов и радиационных явлений в полупроводниках отделениz физики тв`рдого тела.
Рябчиков Юрий Витальевич является автором (соавтором) 46 научных публикаций в рецензируемых зарубежных и российских журналах (на март 2023), индексируемых в базе данных Web of Science, выступает с докладами на международных и российских конференциях, выпустил 2 русскоязычные монографии. Является рецензентом в таких журналах как Applied Surface Science, Journal of Applied Physics, Mechanical Systems and Signal Processing, Journal of Physics and Chemistry of Solids, Diamond & Related Materials и другие. Индекс Хирша на март 2023 года - 15, общее количество цитирований, согласно базе данных Web of Science - 700.
Рябчиков Юрий Витальевич участвовал в организации научных конференций и семинаров, в частности, Advanced Laser Technologies (ALT) в 2014 (Кассис, Франция) и в 2019 году (Прага, Чехия), BiaTri Workshop в 2020 году (Прага, Чехия). Был приглашен ведущим секции "Технология и применения интенсивных, высокоэнергетичных лазеров" WS 102 на конференции, организованной сообществом SPIE в 2019 году в Праге, а также секции "Фотоника: основы, применения и интеграция" на конференции ALT-19 в 2019 году в Праге.
В настоящее время, в тесном сотрудничестве с коллегами из ведущих европейских лабораторий, Рябчиков Юрий Витальевич активно работает над созданием химически чистых композитных и гибридных наноматериалов для таких применений, как нанотермометрия, фотовольтаика, катализ, генерация водорода.
Однако, основное направление научной деятельности Рябчикова Юрия Витальевича связано с применением наноматериалов и лазеров среднего ИК диапазона для целей наномедицины с целью разработки методов неинвазивной диагностики и терапии онкологических и сердечно-сосудистых заболеваний. Данные исследования выполняются в рамках индивидуальной стипендии Марии Кюри (MSCA-IF) LADENTHER.
Основные научные интересы: твердотельные и металл-органические наноструктуры, взаимодействие лазерного излучения с веществом, биомедицинские применения лазеров и наноматериалов, сенсорика, светоизлучающие устройства, фотовольтаика.
Экспериментальные навыки: формирование наноструктур с помощью лазерной абляции, (электро-) химического травления, плазменно-химического осаждения из газовой фазы, электронная (просвечивающая высокого разрешения, сканирующая) и оптическая микроскопия, рентгеновская дифракция, спектроскопия (стационарная и время-разрешённая фотолюминесцентная, Рамановская,
электронный парамагнитный резонанс, эллипсометрия).
Публикации
2023
“Green” Fluorescent–Plasmonic Carbon-Based Nanocomposites with Controlled Performance for Mild Laser Hyperthermia , vol. 10, N11, pp. 1229, (2023)
аннотация
Fluorescent carbon nanodots are a promising nanomaterial for different applications in biophotonics, sensing and optical nanothermometry fields due to their strong fluorescence properties. However, their multi-modal applications are considerably limited, requiring the use of several nanoagents that could solve different tasks simultaneously. In this paper, we report the first experimental results on a facile “green” laser-based synthesis of multi-modal carbon–metallic nanocomposites with tuned optical performance. This simple approach leads to the appearance of finely controlled plasmonic properties in carbon-based nanocomposites whose spectral position is adapted by using an appropriate material. Thus, longer laser ablation provokes 29-fold increase in the absorption intensity of carbon–gold nanocomposites due to the increase in the metal content from 13% (30 s) to 53% (600 s). Despite strong plasmonic properties, the metal presence results in the quenching of the carbon nanostructures’ fluorescence (2.4-fold for C-Au NCs and 3.6-fold for C-Ag NCs for 600 s ablation time). Plasmonic nanocomposites with variable metal content reveal a ~3-fold increase in the laser-to-heat conversion efficiency of carbon nanodots matching the temperature range for mild hyperthermia applications. The findings presented demonstrate a facile approach to expanding the properties of chemically prepared semiconductor nanostructures due to the formation of novel semiconductor–metallic nanocomposites using a “green” approach. Together with the ease in control of their performance, it can considerably increase the impact of semiconductor nanomaterials
- MIROSLAVA FLIMELOVA
AN IMPACT OF THE LASER IRRADIATION TIME ON PROPERTIES OF COLLOIDAL SOLUTIONS OF SILICON NANOPARTICLES , pp. 6807, (2023)
аннотация
The design of semiconductor-metallic nanostructures using pulsed laser ablation in liquids (PLAL) is a very demanding task for biomedical applications being at an early stage of its development. Only few recent papers show the possibility of such a synthesis of composite nanoparticles as well as their perspectives for biosensing applications. However, mechanisms of the laser-stimulated formation of semiconductor-metallic nanoparticles involving several processes are not clarified yet being considerably depended on experimental conditions. In this work, we demonstrated an impact of the laser irradiation of colloidal solutions of silicon nanoparticles at different exposure time in the presence/absence of a gold target. In particular, longer ablation of the metal led to a stronger plasmonic maximum in silicon nanoparticles at around 520 nm. It also decreased the hydrodynamic size from 165 nm to 85 nm as well as the ξ-potential from –46 mV to –30 mV by increasing the ablation time from 0 s to 600 s. At the same time, the lowest electrical conductivity value (~1.5 μS/cm) of the plasmonic nanocomposites was detected at 120 s irradiation time. The highest concentration of synthesized composite nanoparticles (~3·1011 NPs/mL) was achieved at 180 s ablation time. Another purpose of the paper was to reveal an influence of the used laser irradiation on properties of the colloidal solutions of silicon nanoparticles themselves. It was found a considerable decrease of their absorbance with the increase of the laser exposure time that can be associated with the change of their properties (e.g. concentration, size, oxidation state etc.). Thus, the laser irradiation strongly affects properties of colloidal solutions of silicon nanoparticles that must also be taken into account considering possible mechanisms of the formation of composite nanostructures. Presented in the paper fast optical diagnostic can help to determine properties of colloidal solutions of nanocomposites formed by PLAL prior their biomedical or catalytic applications.
Multi-Modal Laser-Fabricated Nanocomposites with Non-Invasive Tracking Modality and Tuned Plasmonic Properties , vol. 13, N9, pp. 1381, (2023)
аннотация
Ultrapure composite nanostructures combining semiconductor and metallic elements as a result of ultrafast laser processing are important materials for applications in fields where high chemical purity is a crucial point. Such nanocrystals have already demonstrated prospects in plasmonic biosensing by detecting different analytes like dyes and bacteria. However, the structure of the nanocomposites, as well as the control of their properties, are still very challenging due to the significant lack of research in this area. In this paper, the synthesis of silicon–gold nanoparticles was performed using various approaches such as the direct ablation of (i) a gold target immersed in a colloidal solution of silicon nanoparticles and (ii) a silicon wafer immersed in a colloidal solution of plasmonic nanoparticles. The formed nanostructures combine both plasmonic (gold) and paramagnetic (silicon) modalities observed by absorbance and electron paramagnetic resonance spectroscopies, respectively. A significant narrowing of the size distributions of both types of two-element nanocrystals as compared to single-element ones is shown to be independent of the laser fluence. The impact of the laser ablation time on the chemical stability and the concentration of nanoparticles influencing their both optical properties and electrical conductivity was studied. The obtained results are important from a fundamental point of view for a better understanding of the laser-assisted synthesis of semiconductor–metallic nanocomposites and control of their properties for further applications.
Plasmon-affected luminescent nanothermometry with multi-band SiNPs/SiNX nanocomposites , vol. 260, pp. 119891, (2023)
аннотация
The design of luminescent multi-functional nanoplatforms that can be simultaneously employed for various
applications is still an important research task nowadays. Nanosilicon is one of the most promising nanomaterial
having unique structural and optoelectronic properties that can be used in biomedicine, optoelectronics, sensing
and nanothermometry. However, its properties do not allow the creation of one luminescent multi-functional
nanoplatform requiring merging of different nanomaterials. In this work, temperature-sensitive silicon-based
nanocomposites with tuned multi-band emission are demonstrated. One can easily achieve the change of their
single- and multi-band photoluminescence spectral position from ~1.6 eV to ~2.9 eV by varying the experimental
parameters. Moreover, the “white” emission of silicon nitride is also observed that can be further applied
for sensing or optoelectronic applications. Furthermore, the presence of silver nanoparticles leads to 80% increase
of the temperature sensitivity of the photoluminescence maximum position (from ~540 μeV/◦ C to ~975
μeV/◦C). The plasmonic nanostructures also considerably modify the ratiometric temperature behavior of
nanocomposite emission. The shown findings suggest perspectives of silicon-based nanostructures as multi-task
luminescent nanoplatforms in the fields of nanothermometry, molecule sensing, optoelectronics and
biomedicine.
Laser-Assisted Nanosynthesis of Fluorescent Carbon Nanocomposites with Variable Plasmonic Properties , pp. 1-1, (2023)
аннотация
Laser-assisted material processing using ultrafast laser sources is an important and promising research direction aiming surface or volumetric modifications of different materials. In particular, pulsed laser ablation in liquids (PLALs) method allows forming a wide set of nanostructures in the form of colloidal solutions. Recently, this approach has also been demonstrated as an effective facile route of the successful formation of silicon-gold nanoparticles (Si-Au NPs) [1] that extended the application of silicon nanostructures in the field of plasmonics [2]. Nevertheless, the laser-assisted nanosynthesis of multi-element semiconductor-metallic nanoparticles is still challenging being at the initial stage of its development.
- M Flimelová, YV Ryabchikov, NM Bulgakova, J Behrends
A Facile Route of Manufacturing and Improvement of Plasmonic Nanostructures towards Magnetic Resonance Applications , pp. 68, (2023)
аннотация
Multicomponent nanostructures consisting of several elements have attracted a broad research interest being served for various aspects in the field of biosensing, catalysis, photovoltaics and biomedicine. Their synthesis by a pulsed laser ablation in a water enables eliminating various side effects originated from chemical contamination. Variable experimental conditions lead to tuning plasmonic and magnetic features influenced by physicochemical reactions during synthesis, thus enhancing their functionality. In this work, we performed synthesis of hybrid AuSi nanoparticles (NPs) with novel modalities by ultrashort laser ablation of bulk gold in water containing silicon NPs. The Au/Si atomic ratio in the nanohybrids was finely varied from 0.5 to 3.5 when changing the initial Si NPs concentration in water from 70 µg/mL to 10 µg/mL respectively. It has been found that the laser-fluence-insensitive silicon content depends on the mass of nanohybrids. A high concentration of paramagnetic defects (2.2 ꞏ1018 spin/g) in polycrystalline plasmonic NPs has been achieved. Our findings can open further prospects for plasmonic nanostructures as contrast agents in optical and magnetic resonance imaging techniques, biosensing and cancer theranostics.
- M Flimelová, YV Ryabchikov, NM Bulgakova, J Behrends
A Facile Route of Manufacturing and Improvement of Plasmonic Nanostructures towards Magnetic Resonance Applications , pp. 68, (2023)
аннотация
Multicomponent nanostructures consisting of several elements have attracted a broad research interest being served for various aspects in the field of biosensing, catalysis, photovoltaics and biomedicine. Their synthesis by a pulsed laser ablation in a water enables eliminating various side effects originated from chemical contamination. Variable experimental conditions lead to tuning plasmonic and magnetic features influenced by physicochemical reactions during synthesis, thus enhancing their functionality. In this work, we performed synthesis of hybrid AuSi nanoparticles (NPs) with novel modalities by ultrashort laser ablation of bulk gold in water containing silicon NPs. The Au/Si atomic ratio in the nanohybrids was finely varied from 0.5 to 3.5 when changing the initial Si NPs concentration in water from 70 µg/mL to 10 µg/mL respectively. It has been found that the laser-fluence-insensitive silicon content depends on the mass of nanohybrids. A high concentration of paramagnetic defects (2.2 ꞏ1018 spin/g) in polycrystalline plasmonic NPs has been achieved. Our findings can open further prospects for plasmonic nanostructures as contrast agents in optical and magnetic resonance imaging techniques, biosensing and cancer theranostics.
2021
- Miroslava Flimelova, Yury V Ryabchikov
A Facile Route of Manufacturing of Silicon-Based Nanostructures with Tuned Plasmonic Properties , vol. 2015, N1, pp. 012128, (2021)
аннотация
An environment-friendly method of pulsed laser ablation in liquids is successfully employed for structural modification of silicon nanoparticles leading to a considerable narrowing of their size distribution accompanied with a reduction of the mean size. Contamination-free conditions of synthesis ensure the chemical purity of formed nanostructures that may reduce toxicity issues. Such a laser-induced modification leads to the appearance of plasmonic properties in semiconductor-based nanomaterials. Their spectral position can easily be varied in the whole visible range. Combined in one nanoparticle properties of semiconductors and noble metals can strongly promote applications of composite laser-synthesized nanoparticles for biosensing (using their plasmonic-based surface-enhanced ability) and bioimaging (using their both optical and magnetic abilities) purposes.
- Miroslava Flimelova, Yury V Ryabchikov
Laser Synthesis of Chemically Pure Multielement Metal-Based Nanostructures , vol. 21, pp. 73-73, (2021)
аннотация
Multicomponent nanostructures consisting of several elements reveal a large research interest being served for various aspects in the field of biomedicine [1, 2]. Combining different elements in a nanoparticle one can easily vary their physicochemical properties in a wide range adjusting their functionality. However, using chemical-based methods for synthesis can considerably obstruct their applications in biomedical fields due to their contamination by chemical residuals. To overcome the aforementioned issues a versatile method of pulsed laser ablation in liquids is widely employed for the synthesis of pure one-and bi-metallic nanostructures widening their functional properties. As a result, they show wide prospects for applications in various fields of biomedicine, eg as contrast agents for magnetic resonance imaging [3, 4]. However, manufacturing of composite metallic-based nanoparticles doped with semiconductor elements by means of pulsed laser ablation method is still challenging being at the early stage of its development. Nevertheless, laser-synthesized metallic-semiconductor nanocomposites have already shown promising perspectives for molecule detection using surface-enhanced Raman scattering (SERS) or infrared absorption techniques (SEIRA) having tracking features as Raman modality or paramagnetic defect labels at the same time [5, 6]. In this work, gold-silicon nanocomposites with dual modalities were fabricated by direct femtosecond laser ablation in deionized water and characterized by structural and optical techniques. A method of chemical content variation is developed allowing fine-tuning of ratio between gold and …
2020
- Yury V Ryabchikov, Jan Behrends
Expedient paramagnetic properties of surfactant-free plasmonic silicon-based nanoparticles , vol. 52, N3, pp. 177, (2020)
аннотация
Surfactant-free multifunctional semiconductor-metallic nanostructures possessing several modalities are formed due to laser-induced structural modification of pure silicon nanoparticles in the presence of gold. It results to variable size-dependent chemical composition examined by energy-dispersive X-ray spectroscopy. Laser-synthesized silicon-based nanocomposites exhibit remarkable both plasmonic and paramagnetic properties. Their plasmonic maxima are found to be easily adjusted in the whole visible spectral range. Influence of resonant laser irradiation on spin behaviour of silicon-gold nanoparticles is established. Their spin–lattice and spin–spin relaxation processes are investigated as well. Such multifunctional nanoparticles can reveal a huge potential for different applications in field of nanomedicine, in particular, for biosensing and bioimaging.
2019
Facile laser synthesis of multimodal composite silicon/gold nanoparticles with variable chemical composition , vol. 21, N4, pp. 85, (2019)
аннотация
Multimodal contamination-free composite silicon/gold nanoparticles are synthesized by “green” laser ablation approach. Their concentration-dependent size distribution and chemical composition are studied by means of transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy. The influence of applied laser fluence on both size distribution and chemical composition is also investigated. The size-dependent chemical composition of formed nanocomposites is analyzed. Optoelectronic properties of silicon/gold nanoparticles as well as their ability to molecule detection using surface-enhanced Raman scattering are studied as well.
- A Yu Kharin, VV Lysenko, A Rogov, Yu V Ryabchikov, A Geloen, I Tishchenko, O Marty, PG Sennikov, RA Kornev, IN Zavestovskaya, V Kabashin, V Yu Timoshenko
Nonlinear optical responses of SI nanocrystals for bioimaging technologies , pp. 36-37, (2019)
UNIQUE APPLICATIONS OF OPTICAL PROPERTIES OF SILICON NANOSTRUCTURES , pp. 3573, (2019)
аннотация
Silicon nanostructures can be prepared by different methods
that considerably change their optical properties depending on
experimental conditions. They are also very sensitive to
molecular environment and external influences that can be
used for multiple applications in different areas. Silicon
nanostructures prepared by laser ablation show large
perspectives for molecular sensing and biomedical applications.
In this paper, an overview of optical properties of silicon
nanostructures with focus on nanoparticles prepared by
ultrafast laser ablation in liquids is provided. It is shown that
they reveal wide prospects for applications in nanobiomedicine
and their unique characteristics can be significantly enhanced
due to laser-induced metal incorporation. Metal inclusions lead
to appearance of plasmonic properties in semiconductor
nanomaterials that can be applied for molecule detection using
surface enhancing of optical response.
- Yury V Ryabchikov, Anatolii Lukianov, Bohdan Oliinyk, Tetyana Nychyporouk, Vladimir Lysenko
Development of silicon nitride-based nanocomposites with multicolour photoluminescence Applied Physics A., vol. 125, pp. 1-7, (2019)
аннотация
Silicon-rich nitride nanocomposites with stable multicolour photoluminescence (PL) are developed in this work. Firstly, a single PL band can be adjusted in the visible spectral range. Secondly, simultaneous emission of an additional PL band is achieved due to boron-doping of the nanocomposites. Impact of thermal annealing of the silicon nitride films in different atmospheres at various temperatures on their PL spectra is studied. Processes responsible for multicolour emission in the boron-doped nanocomposites are discussed. The developed nanocomposites can be further applied for nanothermometry or biosensing applications. They can be also used for synthesis of silicon nanoparticles with multicolour PL.
- Alexander Yu Kharin, Vladimir V Lysenko, Andrei Rogov, Yuri V Ryabchikov, Alain Geloen, Igor Tishchenko, Olivier Marty, Peter G Sennikov, Roman A Kornev, Irina N Zavestovskaya, Andrei V Kabashin, Victor Yu Timoshenko
Bi‐modal nonlinear optical contrast from si nanoparticles for cancer theranostics , vol. 7, N13, pp. 1801728, (2019)
аннотация
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.
- Sanna Uusitalo, Martin Kögler, Alexey Popov, Yury Ryabchikov, Olga Bibikova, Hanna-Leena Alakomi, Riikka Juvonen, Ville Kontturi, Samuli Siitonen, Anna-Liisa Välimaa, Riitta Laitinen, Anton Popov, Gleb Tselikov, Ahmed Al-Kattan, Peter Neubauer, Andrei V K
Surface-enhanced Raman spectroscopy for beverage spoilage yeasts and bacteria detection with patterned substrates and gold nanoparticles (Conference Presentation) , vol. 10907, pp. 1090703, (2019)
аннотация
In food industry, detection of spoilage yeasts such as W. anomalus and B. bruxellensis and pathogens such as certain Listeria and E. coli species can be laborious and time-consuming. In the present study, a simple and repeatable technique was developed for rapid yeast detection using a combination of patterned gold coated polymer SERS substrates and gold nanoparticles [1−4]. For the first time, a state-of-the-art time-gated Raman detection approach was used as a complementary technique to show the possibility of using 532-nm pulsed laser excitation and avoid the destructive influence of induced fluorescence [3]. Conventional nanoparticles synthesized by colloidal chemistry are typically contaminated by non-biocompatible by-products (surfactants, anions), which can have negative impacts on many live objects under examination (cells, bacteria) and thus decrease the precision of bioidentification.
Laser-induced engineering and characterization of multimodal silicon-based nanoparticles , vol. 19, pp. 143-144, (2019)
аннотация
Recent progress in laser technologies provokes comprehensive studies on laser-matter interaction using various materials. One of the most interesting and most important employment of lasers is related to synthesis of new nanomaterials with unique properties for a wide set of applications. Interaction between ultrafast laser radiation and bulk/powder materials in different environments provokes efficient substance removal resulting to formation of nanoparticles with properties depending on experimental conditions [1]. Moreover, it has been shown lately that ultrafast laser irradiation significantly modifies semiconductor nanostructures in the presence of metal forming composite nanoparticles [2, 3]. Such a modification reveals unique modalities ensuring biomedical applications of nanocomposites, in particular, molecule detection by means of surface-enhanced Raman scattering [4]. Nevertheless, study of laser-synthesized composite nanostructures is at an early stage and information about their properties and applications as well is still missed in literature.
Size Modification of Optically Active Contamination‐Free Silicon Nanoparticles with Paramagnetic Defects by Their Fast Synthesis and Dissolution Physica Status Solidi С, vol. 216, N2, pp. 1800685, (2019)
аннотация
Contamination‐free silicon‐based nanoparticles (NPs) with several modalities are developed in this work. They are formed by non‐toxic laser‐assisted decomposition of silicon microgranules homogeneously dispersed in deionized water. Precise control of numerous experimental parameters allows repeatable fine tuning of nanoparticle size solving significant lacks of a direct laser ablation routine. Such a method provokes a huge amount of paramagnetic defect states of optically active silicon NPs that can serve as a contrast agent for magnetic resonance and nonlinear optical imaging. Perspectives of their bioapplication are driven by detected their fast size degradation in a NaCl‐based medium.
2018
Bare laser-synthesized Au-based nanoparticles as nondisturbing surface-enhanced Raman scattering probes for bacteria identification , (2018)
аннотация
The ability of noble
metal-based nanoparticles
(NPs) (Au, Ag)
to drastically enhance
Raman scattering from
molecules placed near
metal surface, termed
as surface-enhanced
Raman scattering
(SERS), is widely
used for identification of trace amounts of biological materials in biomedical, food
safety and security applications. However, conventional NPs synthesized by colloidal
chemistry are typically contaminated by nonbiocompatible by-products (surfactants,
anions), which can have negative impacts on many live objects under
examination (cells, bacteria) and thus decrease the precision of bioidentification. In
this article, we explore novel ultrapure laser-synthesized Au-based nanomaterials,
including Au NPs and AuSi hybrid nanostructures, as mobile SERS probes in tasks
of bacteria detection. We show that these Au-based nanomaterials can efficiently
enhance Raman signals from model R6G molecules, while the enhancement factor
depends on the content of Au in NP composition. Profiting from the observed
enhancement and purity of laser-synthesized nanomaterials, we demonstrate successful
identification of 2 types of bacteria (Listeria innocua and Escherichia coli).
The obtained results promise less disturbing studies of biological systems based on
good biocompatibility of contamination-free laser-synthesized nanomaterials.
Recent Advances in Laser-Ablative Synthesis of Bare Au and Si Nanoparticles and Assessment of Their Prospects for Tissue Engineering Applications , (2018)
аннотация
Driven by surface cleanness and unique physical, optical and chemical properties,
bare (ligand-free) laser-synthesized nanoparticles (NPs) are now in the focus of interest as promising
materials for the development of advanced biomedical platforms related to biosensing, bioimaging
and therapeutic drug delivery. We recently achieved significant progress in the synthesis of bare
gold (Au) and silicon (Si) NPs and their testing in biomedical tasks, including cancer imaging and
therapy, biofuel cells, etc. We also showed that these nanomaterials can be excellent candidates for
tissue engineering applications. This review is aimed at the description of our recent progress in laser
synthesis of bare Si and Au NPs and their testing as functional modules (additives) in innovative
scaffold platforms intended for tissue engineering tasks.
- И.А. Белогорохов, Л.И. Белогорохова, В.Е. Пушкарев
Люминесцентные свойства композитных систем на основе поЛистироЛа и фтаЛоцианинатов эрбиЯ(III) в бЛижней ик обЛасти , (2018)
аннотация
Получены композитные материалы на основе полистирола и фталоцианинатов ErIII одно-, двух- и трёхпалубного
строения, изучены их спектральные люминесцентные характеристики в ближнем ИК (БИК) диапазоне.
Для всех исследованных комплексов в составе композитов характерна 4f фотолюминесценция (ФЛ), которая в случае
моно- и трис(фталоцианината) наблюдается при 1550 нм, в случае же бис(фталоцианината) максимум ФЛ смещён
в коротковолновую область и проявляется при 1440 нм. Проведен сравнительный анализ свойств композитов
и индивидуальных фталоцианиновых соединений в пленках и растворе. Так, например, в случае однопалубного
фталоцианина данную эмиссию удалось зафиксировать впервые именно в матрице полистирола – для индивидуальных
моно(фталоцианинатов) ErIII этот процесс ранее не наблюдался.
- A Danilov, G Tselikov, AV Kabashin, F Wu, VG Kravets, AN Grigorenko, I Ozerov, F Bedu, AA Popov, A Al-Kattan, GI Tselikov, YV Ryabchikov, VP Nirwan, A Fahmi, E Munnier, I Chourpa
Том. 10521. Synthesis and Photonics of Nanoscale Materials XV.-Сер. Synthesis and Photonics of Nanoscale Materials XV , (2018)
- Anton A Popov, Ahmed Al-Kattan, Viraj P Nirwan, Emilie Munnier, Gleb I Tselikov, Yury V Ryabchikov, Igor Chourpa, Amir Fahmi, AV Kabashin
Bare laser-synthesized Si nanoparticles as functional elements for chitosan nanofiber-based tissue engineering platforms , vol. 10521, pp. 10-17, (2018)
аннотация
Methods of femtosecond laser ablation were used to fabricate bare (ligand-free) silicon (Si) nanoparticles in deionized water. The nanoparticles were round in shape, crystalline, free of any impurities, and water-dissolvable, while the dissolution rate depended on the concentration of oxygen defects in their composition. The nanoparticles were then eletrospun with chitosan to form nanoparticle decorated nanofibrous matrices. We found that the functionalization of nanofibers by the nanoparticles can affect the morphology and physico-chemical characteristics of resulting nanostructures. In particular, the presence of Si nanoparticles led to the reduction of fibers thickness, suggesting a potential improvement of fiber’s surface reactivity. We also observed the improvement of thermal stability of hybrid nanofibers. We believe that the incorporated Si nanoparticles can serve as functional elements to improve characteristics …
2017
Surface enhanced infrared absorption spectroscopy based on gold nanostars and spherical nanoparticles , (2017)
аннотация
Plasmonic anisotropic nanoparticles possess a number of hot spots on their surface due to the presence
of sharp edges, tips or vertices, leading to a high electric field strength surrounding the nanostructures. In
this paper, we explore different plasmonic nanostructures, including anisotropic gold nanostars (AuNSts)
and spherical gold nanoparticles, in surface-enhanced infrared absorption spectroscopy (SEIRAS) in an
attenuated total reflection (ATR) configuration. In our experiments, we observed up to 10-times
enhancement of the infrared (IR) absorption of thioglycolic acid (TGA) and up to 2-times enhancement of signals for bovine serum albumin (BSA) protein on plasmonic nanostructure-based films
deposited on a silicon (Si) internal reflection element (IRE) compared to bare Si IRE. The dependence of
the observed enhancement on the amount of AuNSts present at the surface of the IRE has been
demonstrated. Quantitative studies with both, TGA and BSA were performed, observing that the SEIRA
signal can be correlated to the concentration of analyte molecules present within the evanescent field.
The calibration curves in the presence of the AuNSts showed enhanced sensitivity as compared with the
bare Si IRE.We finally compare efficiencies of anisotropic AuNSts and spherical citrate-capped and “bare”
laser-synthesized gold nanoparticles as SEIRAS substrates for the detection of TGA and BSA. The signal
obtained from AuNSts was at least 2 times higher for TGA molecules in comparison with spherical gold
nanoparticles, which was explained by a more efficient generation of hot spots on anisotropic surface
due to the presence of sharp edges, tips or vertices, leading to a high electric field strength surrounding
the AuNSts.
Influence of oxidation state on water solubility of Si nanoparticles prepared by laser ablation in water , (2017)
аннотация
Femtosecond laser fragmentation from preliminarily prepared water-dispersed Si microcolloids was used to synthesize
bare (ligand-free) spherical silicon nanoparticles (Si-NPs) with low size dispersion and controllable mean size from a few
nm to several tens of nm. In order to control the oxidation state of Si-NPs, the fragmentation was performed in normal
oxygen-saturated water (oxygen-rich conditions) or in water disoxygenated by pumping with noble gases (Ag, He) before
and during the experiment (oxygen-free conditions). XPS and TEM studies revealed that Si-NPs were composed of Si
nanocrystals with inclusions of silicon oxide species, covered by SiOx (1 x 2) shell, while the total oxide content
depended whether Si-NPs were prepared in oxygen-rich or oxygen-free conditions. When placed into a dialysis box, waterdispersed
Si-NPs rapidly dissolved, which was evidenced by TEM data. In this case, NPs prepared under oxygen-rich
conditions demonstrated much faster dissolution kinetics and their complete disappearance after 7-10 days, while the
dissolution process of less oxidized counterparts could last much longer (25-30 days). Much fast dissolution kinetics of
more oxidized Si-NPs was attributed to more friable structure of nanoparticle core due to the presence of numerous
oxidation-induced defects. Laser-synthesized Si-NPs are of paramount importance for biomedical applications.
Surface-enhanced Raman spectroscopy for identification and discrimination of beverage spoilage yeasts using patterned substrates and gold nanoparticles , (2017)
аннотация
In the beverage industry, the detection of spoilage yeasts such as Wickerhamomyces anomalus and
Brettanomyces bruxellensis can be labourious and time-consuming. In the present study, a simple and
repeatable technique was developed for rapid yeast detection using a combination of patterned goldcoated
surface-enhanced Raman spectroscopy (SERS) substrates and gold nanoparticles. W. anomalus
and B. bruxellensis showed several characteristic peaks, enabling the discrimination of these yeasts
without chemometric analysis. The control yeast used as an indicator yeast, Rhodotorula mucilaginosa,
showed 7 cell wall-related peaks originating from lipids and haemoproteins. AnalysingW. anomalus SERS
spectra with differently sized and shaped gold nanoparticles revealed the benefit of using either large,
spherical, chemically synthesised gold nanoparticles or small, laser-synthesised, gold-silicon nanoparticles
for yeast detection. Additionally, the spectra showed differences in SERS signal construction for
small molecules and biological cells, as the nanoparticles with best response in biological cell detection
did not excel in small molecule detection. The use of small composite gold-silicon nanoparticles in
combination with the SERS substrate gave distinctive spectra for all detected yeast species.
Cavitation-Free Continuous-Wave Laser Ablation from a Solid Target to Synthesize Low-Size-Dispersed Gold Nanoparticles , (2017)
аннотация
Continuous wave (CW) radiation from a Yb-fiber laser (central
wavelength 1064 nm, power 1–200 W) was used to initiate
ablation of a gold target in deionized water and to synthesize
bare (unprotected) gold nanoparticles. We show that the
formed nanoparticles present a single low-size-dispersed population
with a mean size of the order of 10 nm, which contrasts
with previously reported data on dual populations of nanoparticles
formed during pulsed laser ablation in liquids. The lack
of a second population of nanoparticles is explained by the absence
of cavitation-related mechanism of material ablation,
which typically takes place under pulsed laser action on a solid
target in liquid ambience, and this supposition is confirmed by
plume visualization tests. We also observe a gradual growth of
mean nanoparticle size from 8–10 nm to 20–25 nm under the
increase of laser power for 532 nm pumping wavelength,
whereas for 1064 nm pumping wavelength the mean size 8–
10 nm is independent of radiation power. The growth of the
nanoparticles observed for 532 nm wavelength is attributed to
the enhanced target melting and splashing followed by additional
heating due to an efficient excitation of plasmons over
gold nanoparticles. Bare, low-size-dispersed gold nanoparticles
are of importance for a variety of applications, including biomedicine,
catalysis, and photovoltaics. The use of CW radiation
for nanomaterial production promises to improve the cost efficiency
of this technology.
2016
Nonlinear Optical Properties of Silicon Carbide (SiC) Nanoparticles by Carbothermal Reduction , (2016)
аннотация
SiC nanoparticles by carbothermal reduction show promising properties in terms of second harmonic and multiphoton
excited luminescence. In particular, we estimate a nonlinear eciency = 17 pm/V, as obtained
by Hyper Rayleigh Scattering. We also present results of cell labelling to demonstrate the potential use of SiC
nanoparticles for nonlinear bioimaging by simultaneous detection of second harmonic and luminescence.
Ultrapure laser-synthesized Sibased nanomaterials for biomedical applications: in vivo assessment of safety and biodistribution , (2016)
аннотация
Si/SiOx nanoparticles (NPs) produced by laser ablation in deionized water or aqueous biocompatible
solutions present a novel extremely promising object for biomedical applications, but the interaction
of these NPs with biological systems has not yet been systematically examined. Here, we present
the first comprehensive study of biodistribution, biodegradability and toxicity of laser-synthesized
Si-SiOx nanoparticles using a small animal model. Despite a relatively high dose of Si-NPs (20 mg/kg)
administered intravenously in mice, all controlled parameters (serum, enzymatic, histological etc.) were
found to be within safe limits 3 h, 24 h, 48 h and 7 days after the administration. We also determined
that the nanoparticles are rapidly sequestered by the liver and spleen, then further biodegraded
and directly eliminated in urine without any toxicity effects. Finally, we found that intracellular
accumulation of Si-NPs does not induce any oxidative stress damage. Our results evidence a huge
potential in using these safe and biodegradable NPs in biomedical applications, in particular as vectors,
contrast agents and sensitizers in cancer therapy and diagnostics (theranostics).
Ultrapure laser-synthesized Si nanoparticles with variable oxidation states for biomedical applications , (2016)
аннотация
We employ a method of femtosecond laser fragmentation of preliminarily prepared water-dispersed
microcolloids to fabricate aqueous solutions of ultrapure bare Si-based nanoparticles (Si-NPs) and assess
their potential for biomedical applications. The nanoparticles appear spherical in shape, with low size
dispersion and a controllable mean size, from a few nm to several tens of nm, while a negative surface
charge (35 mV 0.10 according to z-potential data) provides good electrostatic stabilization of
colloidal Si-NP solutions. Structural analysis shows that the Si-NPs are composed of Si nanocrystals with
inclusions of silicon oxide species, covered by a SiOx (1 o x o 2) shell, while the total oxide content
depends on whether the fragmentation is performed in normal oxygen-saturated water (oxygen-rich
conditions) or in water deoxygenated by pumping with noble gases (Ag or He) before and during the
experiment (oxygen-free conditions). Our dissolution tests show the excellent water-solubility of all the
NPs, while more oxidized NPs demonstrate much faster dissolution kinetics, which is explained by
oxidation-induced defects in the core of the Si-NPs. Finally, by examining the interaction of the NPs
with human cells after 72 h of incubation at different concentrations, we report the absence of any
adverse effects of the NPs up to high concentrations (50 mg mL1) and a good internalization of NPs via a
classical endocytosis mechanism. Possessing far superior purity compared to their chemically synthesized
counterparts and enabling a variety of imaging and therapeutic functionalities, the laser-synthesized
Si-NPs are promising for safe and efficient applications in nanomedicine.
Si nanoparticles as sensitizers for radio frequency-induced cancer hyperthermia , (2016)
аннотация
We review our recently obtained data on the employment of Si nanoparticles as sensitizers of radiofrequency (RF) -
induced hyperthermia for mild cancer therapy tasks. Such an approach makes possible the heating of aqueous
suspensions of Si nanoparticles by tens of degrees Celsius under relatively low intensities (1–5 W/cm2) of 27 MHz RF
radiation. The heating effect is demonstrated for nanoparticles synthesized by laser ablation in water and mechanical
grinding of porous silicon, while laser-ablated nanoparticles demonstrate a remarkably higher heating rate than porous
silicon-based ones for the whole range of the used concentrations. The observed RF heating effect can be explained in
the frame of a model considering the polarization of Si NPs and electrolyte in the external oscillating electromagnetic
field and the corresponding release of heat by electric currents around the nanoparticles. Our tests evidence relative
safety of Si nanostructures and their efficient dissolution in physiological solutions, suggesting potential clearance of
nanoparticles from a living organism without any side effects. Profiting from Si nanoparticle-based heating, we finally
demonstrate an efficient treatment of Lewis Lung carcinoma in vivo. The obtained data promise a breakthrough in the
development of mild, non-invasive methods for cancer therapy.
Structural properties of gold-silicon nanohybrids formed by femtosecond laser ablation in water at different fluences , (2016)
аннотация
A gold target was ablated by femtosecond laser radiation in aqueous solutions of preliminarily prepared Si nanoparticles.
The ablation process led to the formation of Au-based spherical colloids with the mean size around 5-10 nm and a weak
abundance of larger species. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) analysis
revealed the presence of Au and Si in colloid composition, while the stoichiometry of colloids did not depend on laser
fluence during the fabrication experiments. The formation of Au-Si nanohybrid structure was explained by an effect of
the interaction of laser-ablated Au nanoclusters with water-dispersed Si nanoparticles. The fabricated structures can be of
importance for biomedical, catalysis, and photovoltaics applications.
Laser ablative nanostructuring of Au in liquid ambience in continuous wave illumination regime , (2016)
аннотация
We study surface modifications and fabrication of nanoparticles under ablation of water-immerged Au target by a
moving beam of continuous wave Ytterbium fiber laser (532, 1064 nm). Our analysis of the target surface reveals the
presence of solidified nanoscale Au nanoparticles distributed over the crater of the laser beam, which is consistent with
the presence of metal melting and evaporation effects. Optical imaging of the hydrodynamic process shows the presence
of convective flows leading to a strong mixing of the liquid medium during the laser ablation process. The laser ablation
process results in the production of gold nanoparticle colloids with average particle sizes smaller than 10 nm under
relatively narrow size dispersion. Au nanoparticles prepared by CW laser ablation of Au in deionized water are of
importance for a variety of applications, including biomedical, catalysis and electrocatalysis, photovoltaics etc.
Detection of Listeria innocua on roll-to-roll produced SERS substrates with gold nanoparticles , (2016)
аннотация
The rapid and accurate detection of food pathogens plays a critical role in the early prevention of foodborne
epidemics. Current bacteria identification practices, including colony counting, polymerase chain reaction
(PCR) and immunological methods, are time consuming and labour intensive; they are not ideal for
achieving the required immediate diagnosis. Different SERS substrates have been studied for the
detection of foodborne microbes. The majority of the approaches are either based on costly patterning
techniques on silicon or glass wafers or on methods which have not been tested in large scale
fabrication. We demonstrate the feasibility of analyte specific sensing using mass-produced, polymerbased
low-cost SERS substrate in analysing the chosen model microbe with biological recognition. The
use of this novel roll-to-roll fabricated SERS substrate was combined with optimised gold nanoparticles
to increase the detection sensitivity. Distinctive SERS spectral bands were recorded for Listeria innocua
ATCC 33090 using an in-house build (785 nm) near infra red (NIR) Raman system. Results were
compared to both those found in the literature and the results obtained from a commercial time-gated
Raman system with a 532 nm wavelength laser excitation. The effect of the SERS enhancer metal and
the excitation wavelength on the detected spectra was found to be negligible. The hypothesis that
disagreements within the literature regarding bacterial spectra results from conditions present during the
detection process has not been supported. The sensitivity of our SERS detection was improved through
optimization of the concentration of the sample inside the hydrophobic polydimethylsiloxane (PDMS)
wells. Immunomagnetic separation (IMS) beads were used to assist the accumulation of bacteria into the
path of the beam of the excitation laser. With this combination we have detected Listeria with gold
enhanced SERS in a label free manner from such low sample concentrations as 104 CFU ml1.
2014
Enhanced Thermal Sensitivity of Silicon Nanoparticles Embedded in (Nano-Ag/)SiNx for Luminescent Thermometry , (2014)
аннотация
Steady-state photoluminescence of silicon nanoparticles embedded
in solid-state (nano-Ag/)SiNx thin films at above room temperature is
studied and compared to silicon nanoparticles dispersed in low-polar liquids.
Roles of local surface plasmons as well as general mechanisms responsible for the
temperature-dependent photoluminescence are pointed out. Thermal sensitivities
of photoluminescence spectral shape, maximum position, and full width at halfmaximum
are estimated and application of the (nano-Ag/)SiNx layers as
photoluminescent thermal screens is proposed.
Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy , (2014)
аннотация
Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced
hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid
side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced
therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean
laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles
to temperatures above 45-506C under relatively low nanoparticle concentrations (,1 mg/mL) and RF
radiation intensities (1–5 W/cm2). For both types of nanoparticles the heating rate was linearly dependent
on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating
rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4 mg/mL.
The observed effect is explained by the Joule heating due to the generation of electrical currents at the
nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an
efficient treatment of Lewis lung carcinomain vivo. Combined with the possibility of involvement of parallel
imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed
method promises a new landmark in the development of new modalities for mild cancer therapy.
2013
Photoluminescence thermometry with alkyl-terminated silicon nanoparticles dispersed in low-polar liquids , (2013)
аннотация
Steady-state and time-resolved photoluminescence of silicon
nanoparticles dispersed in low-polar liquids at above room
temperature is studied. The roles of low-polar liquids as well
as mechanisms responsible for their temperature-dependent
photoluminescence are discussed. The thermal sensitivity of
the photoluminescence is estimated and application of the
nanoparticles as nanothermometers is proposed.
Design of microporous mixed zinc–nickel triazolate metal–organic frameworks with functional ligands , (2013)
аннотация
We report two new microporous mixed-metal triazolate based
MOFs made from zinc and nickel salts combined with either
1,2,4-triazole or 3,5-diamino-1,2,4-triazole. Their structures,
refined from X-ray powder diffraction, their CO2 adsorption and
photoluminescent properties show a direct correlation with the
structure of their parent organic ligand.
Photoluminescence of silicon nanoparticles chemically modified by alkyl groups and dispersed in low-polar liquids , (2013)
аннотация
A detailed comparative analysis of photoluminescence
behavior of silicon nanoparticles in air
and dispersed in low-polar liquids is reported. Efficient
dispersion and excellent stability of the chemically
modified nanoparticles in low-polar liquids are
achieved. Influence of the chemical functionalization
and of the low-polar liquids on steady-state and timeresolved
photoluminescence of the silicon nanoparticles
is investigated. Role of low-polar liquids on
recombination mechanisms taking place in the nanoparticles
is discussed in terms of Fo¨rster resonant
energy transfer processes. Effect of exciting laser
power on photoluminescence spectra of the silicon
nanoparticles both in air and in low-polar liquids is
investigated and the electronic mechanisms involved
into the observed phenomena are discussed.
2012
Luminescence behavior of silicon and carbon nanoparticles dispersed in low-polar liquids , (2012)
аннотация
A comparative photoluminescence analysis of as-prepared and chemically modified (by alkyl chains -C18H37) silicon
and carbon nanoparticles dispersed in low-polar liquids is reported. Influence of the low-polar liquid nature and
ambient temperature on photoluminescence of the nanoparticles has been investigated from the point of view of
their possible application as thermal nanoprobes.
Transport and Spectroscopic Features of Composite Semiconductor Material Based on Poly[2-Methoxy-5- (2-Ethyl-Hexyloxy)-1,4-Phenylene-Vinylene] , (2012)
аннотация
For the first time we report on investigations of the electrical transport properties of multicomponent
polymer systems based on [2-methoxy-5-(2-etilgeksiloksi)-1,4-phenylene vinylene-] (MEH-PPV)
molecules. The temperature dependences of dark conductivity on DC allow us to find a polaron
mechanism of the charge transport with activation energy of 0.058 eV, which can be explained by
an influence of phthalocyanine complex embedded in a polymer matrix as nanoimpurity. Theoretical
calculations with Molecular Mechanics Universal Force Field (UFF) reveal that a set of Pc molecules
has the dipole moment of 1.1276 Debye and its direction is from nitrogen atoms in the center of
Pc ring to benzene groups in the periphery of the Pc molecule. Infrared optical spectroscopy data
demonstrate that incorporation of the phthalocyanine complexes into the polymeric matrix leads to
appearance of a set of the absorption lines in the region of 750÷3340 cm−1.
Vibronic States in Organic Semiconductors Based on NonMetal Naphthalocyanine. Detection of Heterocyclic Phthalocyanine Compounds in a Flexible Dielectric Matrix , (2012)
аннотация
The vibronic properties of semiconductor structures based on nonmetal naphthalocyanine molecules are studied using IR and Raman spectroscopy methods. New absorption lines in the transmission spectra of such materials are detected and identified. Three transmission lines are observed in the range 2830–
3028 cm–1, which characterize carbon–hydrogen bonds of peripheral molecular groups. Their spectral positions are 2959, 2906, and 2866 cm–1. It is detected that the phthalocyanine ring can also exhibit its specific
vibronic properties in the Raman spectra at 767, 717, and 679 cm–1. The naphthalocyanine molecule in the
organic dielectric matrix of microfibers is described using IR spectroscopy. It is shown that the set of vibrations characterizing the isoindol group, pyrrole ring, naphtha group, and C–H bonds, allows an accurate
enough description of the vibronic states of the naphthalocyanine complex in complex heterostructures to be
made. The spectral range with fundamental modes, characterizing a naphthalocyanine semiconductor in a
heterostructure, is 600–1600 cm–1. A comparison of the compositions of complex systems with a similar heterostructure containing lutetium diphthalocyanine demonstrated few errors.
2011
Features of the Spectral Dependences of Transmittance of Organic Semiconductors Based on TertButyl Substituted Lutetium Phthalocyanine Molecules , (2011)
аннотация
Vibronic properties of organic semiconductors based on tertabutyl substituted phthalocyanine
lutetium diphthalocyanine molecules are studied by IR and Raman spectroscopy. It is shown that substitution
of several carbon atoms in initial phthalocyanine (Pc) ligands with 13C isotope atoms causes a spectral shift in
the main absorption lines attributed to benzene, isoindol, and peripheral C–H groups. A comparison of spectral characteristics showed that the shift can vary from 3 to 1 cm–1.
Infrared Spectroscopy of Semiconductor Structures Based on Alkyl-Substituted Lanthanide (III) Clam-Shell Mono-, Di-, and Di-Trisphthalocyanine Complexes , (2011)
аннотация
Optical properties of semiconductor structures based on clam-shell phthalocyanine complexes
have been studied by Fourier Transform Infrared Spectrometry. Transmission spectra of metal-free
monophthalocyanine, bis-phthalocyanine of Eu and Eu di-tris-phthalocyanine organic semiconductors
were have been obtained and analyzed. Comparison of spectral data from different clam-shell
complexes revealed that magnetic f–f interaction of Eu atoms increase the energy of vibronic
states which is clearly indicated by the spectral shift of absorption lines position. A new set of
absorption lines in the 2360÷2341 cm−1 range was observed. It was suggested that these lines
correspond to vibrations of orto-bis(oximetil)phenol group. It was found that vibronic modes of the
phtalocyanine-ring reveal several absorption lines with spectral coordinates 526 cm−1, 502 cm−1,
484 cm−1, 467 cm−1 in the far infrared region.
Photosensitized Generation of Singlet Oxygen in Powders and Aqueous Suspensions of Silicon Nanocrystals , (2011)
аннотация
The photoluminescence spectra and kinetics in powders and aqueous suspensions produced from
porous silicon layers are studied. The systematic features of photosensitized generation of singlet oxygen by
silicon nanocrystals in the samples are established. The dependence of the efficiency of generation of singlet
oxygen on the pressure of molecular oxygen is analyzed. It is concluded that the generation can be described
on the basis of concepts of energy transfer from photoexcited silicon nanocrystals to oxygen molecules
adsorbed at the nanocrystal surface to the concentration described by Langmuir’s adsorption model. The
processes limiting the efficiency of photosensitized generation of singlet oxygen in the systems are discussed.
Study of the Transport Properties of Organic Semiconductors Based on Europium Diphthalocyanine and bitrisPhthalocyanine Complexes with orthobis(Oxymethyl)Phenyl Bridge and Based on Erbium and Europium Dinaphthalocyanine Complexes , (2011)
аннотация
The transport properties of organic semiconductors based on europium diphthalocyanine and bi-tris-phthalocyanine complexes with ortho-bis(oxymethyl)phenyl bridge and based on europium and erbium
dinaphthalocyanine are studied. The temperature dependences of the dc conductivity for all types of the
structures under study are obtained; it is shown that all dependences include two activation portions. For
hightemperature portions, the activation energies are determined as 0.85 eV for europium diphthalocyanine
with the ortho-bis(oxymethyl)phenyl bridge, 1.135 eV for europium bitrisphthalocyanine with the orthobis(oxymethyl)phenyl bridge, 0.98 eV for europium dinaphthalocyanine, and 1.18 eV for erbium dinaphthalocyanine. For the low-temperature activation portion, it is shown that lanthanide ions and their bond with
a ligand make the dominant contribution to the conductivity of the structures under study.
2010
Вибронные свойства органических полупроводников на основе фталоцианиновых комплексов с несимметричным распределением электронной плотности , (2010)
аннотация
Посвящена исследованию оптических свойств органических полупроводников на основе ди- и трифтало-
цианиновых комплексов лантанидов (III) с несимметричным распределением электронной плотности. Полу-
чены твердые пленки дифталоцианина ClPcLutBuPc и трифталоцианина ClPcEuBuPcLuBuPc (ClPc = 2, 3, 9, 10,
16, 17, 23, 24-октахлорфталоцианинат, tBuPc = 2(3), 9(10), 16(17), 23(24)-тетра-третбутилфталоцианинат,
BuPc = 2, 3, 9, 10, 16, 17, 23, 24-октабутилфталоцианинат) и исследованы их спектры пропускания в средней
ИК-области. Расшифровка спектров пропускания показала, что усложнение структуры молекул фталоцианина
приводит к тому, что в области 1400−1450 см−1 изоиндольная группа может проявлять вибронные свойства
в виде четырех линий поглощения. В дальней ИК-области обнаружены новые линии поглощения, наличие
которых может быть связано с присутствием хлор-углеродных связей.
2009
EPR and photoluminescence diagnostics of singlet oxygen generation on porous silicon surface , (2009)
аннотация
Electron paramagnetic resonance and photoluminescence
spectroscopy are used to investigate photosensitized generation
of singlet oxygen in the porous silicon layers. The singlet
oxygen concentration in the samples was estimated at various
oxygen pressures. The time of energy transfer from excitons
confined in Si nanocrystals to adsorbed O2 molecules on silicon
nanocrystal surface and photosensitization efficiency are
found to depend on the porosity of the samples. The singlet
oxygen generation efficiency increases strongly for porous
silicon with high (>80%) porosity.
2008
Оптические и электрические свойства полупроводниковых структур на основе бутилзамещенных фталоцианинов, содержащих ионы эрбия , (2008)
Photoluminescence in Semiconductor Structures Based on Butyl-Substituted Erbium Phthalocyanine Complexes , (2008)
аннотация
The study is concerned with the luminescence properties of ensembles of semiconductor structures
containing organic phthalocyanine molecules with erbium ions as complexing agents. The photoluminescence
spectra of the structures of the type of erbium monophthalocyanine, bisphthalocyanine, and triphthalocyanine
are recorded. The photoluminescence peaks are detected at the wavelengths 888, 760, and 708 nm (and photon
energies 1.4, 1.6, and 1.75 eV) corresponding to electronic transitions within the organic complexes. It is found
that, when a metal complexing agent is introduced into the molecular structure of the ligand, the 708 nm luminescence
peak becomes unobservable. It is shown that, in the bisphthalocyanine samples, the photoluminescence
signal corresponding to transitions from the 4
F
9/2
level of erbium ions is enhanced.
2007
Silicon nanocrystals as efficient photosensitizer of singlet oxygen for biomedical applications , (2007)
аннотация
Luminescent silicon nanocrystals (nc-Si) are shown to be efficient photosensitizers of singlet oxygen (SO) generation.
Photoluminescence (PL) spectroscopy method is used to study the mechanism and efficiency of the SO
photosensitization in gaseous and aqueous ambiences. In vitro experiments demonstrated that the SO, photosensitized by
nc-Si dispersed in nutrient solutions, could kill cancer cells. This finding opens a broad opportunity for biomedical
applications of nc-Si, e.g. for the photodynamic therapy of cancer or antibacterial treatments.
Dependence of the singlet oxygen photosensitization efficiency on morphology of porous silicon , (2007)
аннотация
We investigate the effect of oxygen molecule adsorption on the photoluminescence of porous silicon films
of different porosity. The experimental results are explained by the photosensitization of singlet oxygen
generation due to the energy transfer from excitons confined in Si nanocrystals to O2 molecules adsorbed
on the Si nanocrystal surface. The energy transfer time and photosensitization efficiency are found to depend
on porosity of the samples. The singlet oxygen generation efficiency increases strongly for porous
silicon with high (> 80%) porosity.We investigate the effect of oxygen molecule adsorption on the photoluminescence of porous silicon films
of different porosity. The experimental results are explained by the photosensitization of singlet oxygen
generation due to the energy transfer from excitons confined in Si nanocrystals to O2 molecules adsorbed
on the Si nanocrystal surface. The energy transfer time and photosensitization efficiency are found to depend
on porosity of the samples. The singlet oxygen generation efficiency increases strongly for porous
silicon with high (> 80%) porosity.
2006
Charge Carrier Transport in a Structure with Silicon Nanocrystals Embedded into Oxide Matrix , (2006)
аннотация
Current–voltage characteristics of Al/SiO
2
/
c
-Si structures with silicon nanocrystals (
nc
-Si) in the
oxide layer are studied in a wide temperature range. The analysis based on the experimental data has shown that
thermostimulated tunneling via electron states in
nc
-Si is a most probable mechanism of charge carrier transport
in these structures.
Femtosecond Nanostructuring of Silicon Surfaces , (2006)
аннотация
Nanostructures were formed upon the irradiation of single-crystal silicon surfaces with femtosecond laser
pulses. These nanostructures were detected using scanning electron microscopy, Raman spectroscopy, and a
photoluminescence technique.
Silicon Nanocrystals As Photosensitizers of Active Oxygen for Biomedical Applications , (2006)
аннотация
Silicon nanocrystals dispersed in water have been used to photosensitize the generation of active oxygen. The
photosensitizing efficiency has been estimated through the quenching of the exciton photoluminescence of silicon
nanocrystals. Experiments have revealed a strong (up to 80%) decrease in the number of cancer mouse
fibroblast cells when they come into contact with photoexcited silicon nanocrystals. The obtained results show
that the use of silicon nanocrystals for biomedical applications, in particular, for photodynamic therapy of cancer,
is feasible.
Electron-paramagnetic resonance and photoluminescence study of Si nanocrystals-photosensitizers of singlet oxygen molecules , (2006)
аннотация
Si nanocrystals formed by electrochemical porosifying of c-Si wafers are investigated by means of the electron-paramagnetic resonance
(EPR) and photoluminescence (PL) techniques. The PL spectra and transients give evidence of the photosensitization of singlet
oxygen molecules by the energy transfer from excitons confined in Si nanocrystals to oxygen molecules adsorbed on the nanocrystal surfaces.
The EPR experiments show that the singlet oxygen generation is accompanied by a slowing down of the spin-spin relaxation time
of Si dangling bonds on the nanocrystal surfaces. This effect is explained by the transition of a large part of the adsorbed O2 molecules in
their ground (triplet) states to the excited (singlet) ones. The EPR data allow us to estimate the concentration of the photosensitized
singlet oxygen molecules to be on the order of 1018 cm3.
2004
Особенности фотолюминесценции органических молекул в пористом кремнии , (2004)
Влияние адсорбции донорных и акцепторных молекул на рекомбинационные свойства кремниевых нанокристаллов , (2004)
2003
ОСОБЕННОСТИ ВЗАИМОДЕЙСТВИЯ АДСОРБИРОВАННЫХ ОРГАНИЧЕСКИХ МОЛЕКУЛ С МАТРИЦЕЙ ПОРИСТОГО КРЕМНИЯ , (2003)
недавние публикации
Расположение корпуса на территории института
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