ВИЗУАЛИЗАЦИЯ НАНОЧАСТИЦ LaF3, ДОПИРОВАННЫХ Nd3+, ДЛЯ БИОИМИДЖИНГА В БЛИЖНЕМ ИНФРАКРАСНОМ ДИАПАЗОНЕ ПО АП-КОНВЕРСИОННОЙ ЛЮМИНЕСЦЕНЦИИ ПРИ МИКРОСКОПИИ С МУЛЬТИФОТОННЫМ ВОЗБУЖДЕНИЕМ

Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd3+ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd3+ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd3++:LaF NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs inVIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy.Последние разработки в области биофотоники способствуют повышению интереса к неорганическим наночастицам (НЧ), допированным ионами Nd3+, из-за их поглощения в ближнем инфракрасном (БИК) спектральном диапазоне. Эти НЧ являются перспективными зондами для глубокой визуализации тканей, в то же время они могут служить локальными термометрами в биологических тканях. Несмотря на хорошие возможности визуализации НЧ с ионами Nd3+ в БИК спектральном диапазоне, при изучении внутриклеточного распределения этих НЧ с использованием коммерчески доступных флуоресцентных микроскопических систем возникают трудности из-за ограниченности выбора подходящих детекторов люминесценции. Однако, ионы Nd3+ способны преобразовывать БИК излучение в видимый свет, демонстрируя ап-конверсионные свойства. В этой работе мы определили оптимальные параметры для возбуждения ап-конверсионной люминесценции НЧ Nd3+: LaF в живых клетках и сравнили распределение НЧ внутри клеток культуры человеческих макрофагов THP-1, полученное двумя методами. Во-первых, путем регистрации ап-конверсионной люминесценции НЧ в видимом диапазоне при многофотонном возбуждении в БИК диапазоне спектра с использованием лазерной сканирующей конфокальной микроскопии и, во-вторых, с использованием просвечивающей электронной микроскопии

Visualization of Nd3+-doped Laf3 Nanoparticles For Near Infrared Bioimaging via Upconversion Luminescence at Multiphoton Excitation Microscopyvisualization of Nd3+-doped Laf3 Nanoparticles For Near Infrared Bioimaging via Upconversion Luminescence at Multiphoton Excitation Microscopy

Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd 3+ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd 3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd 3+ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd 3+ :LaF 3 NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs in VIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy

Effect of phase composition on X-ray absorption spectra of ZrO2 thin films

The X-ray photoabsorption spectra of ZrO2 films with different phase compositions were measured. The analysis of the results obtained shows that due to the site-sensitivity the X-ray photoabsorption spectroscopy is an attractive method for characterization of the ZrO2 structure. This allows application of the X-ray spectroscopy in investigation of the crystal structure in the various stages of the thin film growth including the initial stage of the ZrO2 growth. (c) 2006 Elsevier B.V. All rights reserved

Study of thin oxide films by electron, ion and synchrotron radiation beams

Titanium oxide and zirconium oxide thin films deposited on silicon substrates were characterised using electron probe microanalysis (EPMA), Rutherford backscattering spectroscopy (RBS), time-of-flight elastic recoil detection analysis (TOF-ERDA) and scanning photoelectron microscopy (SPEM). The composition and mass thickness of the films were determined and the results of different methods compared. It was revealed that the synchrotron radiation used for SPEM studies caused considerable modification of zirconia films grown at low temperatures