Fluoride nanocrystals co-doped with lanthanide ions are well known due to the possibility of conversion near-infrared (NIR) radiation into photoluminescence with large anti-Stokes shift. Owing to upconversion effect, such nanomaterials have shown great potential in photonics and biomedicine. However, fluoride nanoparticles can be reconfigured to photoluminescence with a Stokes shift into the near-infrared region of the spectrum. In this work, we focused on the properties of NaRF4: Yb3+, Er3+, Ce3+ (R = Y, Lu) nanoparticles exhibiting intense stokes luminescence in the vicinity of 1530 nm at 975 nm excitation. Photoluminescence quantum efficiency of synthesized nanoparticles was evaluated as 28% at 0.6 W/cm2 excitation intensity. Based on the photoluminescent properties of nanoparticles we designed compact waveguide amplifier for C-band telecommunication and developed time gated imaging system for NIR-to-NIR biovisualization.

Технология 3D-печати стала ключевой движущей силой в изменении парадигмы производственного процесса в различных отраслях промышленности. Новой вехой в 3D-печати может стать технология инфракрасной полимеризации, основанная на достижениях в области синтеза наноматериалов, способных эффективно преобразовывать излучение ближнего ИК-диапазона спектра в УФ-свет. Эта инновационная технология может проложить путь к разработке множества решений в промышленности и предвещает новые рубежи для фотоники, оптоэлектроники и биомедицины. В обзоре представлено краткое обобщение имеющихся достижений, а также ограничения, сдерживающие развитие технологии ИК-фотополимеризации.

AbstractWe propose a method for obtaining a fluorescence tomographic image for visualization and diagnosis of tissues of a living organism. The method is based on the excitation of the luminescence of multicolor upconverting nanoparticles localized in the depth of the biological tissue or a phantom imitating it by IR light. By recording the changes in the shape of the spectrum of the intensity of luminescence radiation from luminescent nanoparticles on the surface of the tissue, it is possible to obtain information about the depth of their occurrence. To implement this approach, upconverting nanoparticles were synthesized on the base of β-NaYF_4 crystal matrix doped with rare-earth elements Yb^3+, Er^3+, and Tm^3+. The luminescence spectra of the produced nanoparticles upon excitation at a wavelength of 980 nm contain three narrow bands with maxima at wavelengths 540, 655, and 800 nm.

AbstractDetection systems with deferred registration of luminescence signals are promising for performing complex tasks of imaging of biological objects due to their simplicity and low cost. In the present work, β‑NaYF_4:Tm^3+Yb^3+/NaYF_4 nanocrystals with anti-Stokes photoluminescence have been used in deferred registration systems. It has been shown that there is a significant time delay between the exciting laser pulse and luminescence signal, which makes it possible to use this class of nanoparticles in the creation of wide-field imaging systems with deferred registration. The possibility of using nanoparticles for detecting a photoluminescence signal in the second transparency window of biotissue has been demonstrated. This system can be based on the resonance excitation and detection of the photoluminescence signal of Yb^3 + ions.

A new acrylic monomer derived from perfluoro-2-trichloromethylisopropanol was synthesized. Poly(perfluoro-2-trichloromethylisopropyl acrylate) was prepared by radical bulk polymerization, and its physicochemical properties were studied. It was found that the prepared polyacrylate can be used to manufacture optical waveguides.

Актуальным направлением в современной медицинской диагностике является создание нацеленных на патологические мишени конструкций на основе фотолюминесцентных наночастиц, обладающих высокой фото- и химической стабильностью, а также спектрами поглощения и испускания фотолюминесценции в области «окна прозрачности» биоткани. В работе получена двухкомпонентная конструкция на основе антистоксовых нанофосфoров (НАФ) и противоопухолевых мини-антител 4D5scFv для селективного мечения клеток, гиперэкспрессирующих опухолевый маркер HER2, характерный для целого ряда метастазирующих опухолей человека. Высокоаффинная белковая пара барстар : барназа (Bs : Bn), обладающая чрезвычайной устойчивостью в широком диапазоне pH и температур, использована в качестве молекулярного адаптера, обеспечивающего самосборку двухкомпонентной конструкции. На клетках аденокарциномы молочной железы человека SK-BR-3, гиперэкспрессирующих HER2, показана высокая избирательность связывания полученной двухкомпонентной конструкции 4D5scFv-Bn : Bs-НАФ с опухолевыми клетками. Предложенный подход позволяет получать аналогичные конструкции для визуализации различных специфических маркеров в патогенных тканях, в том числе в злокачественных новообразованиях.

It has been found that the Curie temperature (T C ≈ 300 K) in nonstoichiometric Si1 − x Mn x alloys slightly enriched in Mn (x ≈ 0.52–0.55) in comparison to the stoichiometric manganese monosilicide MnSi becomes about an order of magnitude higher than that in MnSi (T C ∼ 30 K). Deviations from stoichiometry lead to a drastic decrease in the density of charge carries (holes), whereas their mobility at about 100 K becomes an order of magnitude higher than the value characteristic of MnSi. The high-temperature ferromagnetism is ascribed to the formation of defects with the localized magnetic moments and by their indirect exchange interaction mediated by the paramagnetic fluctuations of the hole spin density. The existence of defects with the localized magnetic moments in Si1 − x Mn x alloys with x ≈ 0.52–0.55 is supported by the results of numerical calculations performed within the framework of the local-density-functional approximation. The increase in the hole mobility in the nonstoichiometric material is attributed to the decay of the Kondo (or spin-polaron) resonances presumably existing in MnSi.