Sol-gel coatings for photolithography on nanoporous anodic alumina and aluminum

The results of the patterned microstructures fabrication through electrochemical anodizing, sol-gel synthesis, photolithography and chemical etching are presented. The continuous xerogel films were used as a protective mask. They are good alternative to metal in photolithography. Perspectives of application of these structures in planar optoelectronics are discussed

Enhancement of Raman light scattering in dye-labeled cell membrane on metal-containing conducting polymer film

An enhanced Raman spectroscopy method based on a plasmon resonance in ultrathin metal-containing LB-film deposited on nanoporous anodic alumina supports has been proposed. This material has been utilized to enhance Raman scattering of light in fluorescent-labeled subcellular membrane structures. It has been shown that the plasmon resonance between vibrational modes of the organometallic complexes monolayers and dye-labeled subcellular structures happens. It makes possible to detect interactions between living cell monolayers and an extracellular matrix

Optical Properties of Valve Metals Functional Thin Films Obtained by Electrochemical Anodization on Transparent Substrates

Nanostructured aluminum, tantalum, and vanadium oxide layers on glass substrates were obtained by electrochemical anodizing in oxalic and sulfuric–oxalic electrolytes. The morphological and optical properties of the obtained structures were investigated experimentally by scanning electron microscopy and transmission spectroscopy. Obtained oxide coatings are quasi-ordered arrays of vertical (aluminum oxide/tantalum oxide, aluminum oxide/vanadium oxide, and aluminum oxide obtained in the oxalic electrolyte) or non-ordered tree-like (aluminum oxide obtained in the sulfuric–oxalic electrolyte) pores depending on the initial film metal and anodizing technology. The light transmission in the range of 750–1200 nm is up to 60% for aluminum oxide/tantalum oxide/glass (annealed) and quasi-ordered aluminum oxide/glass structures, and around 40% for aluminum oxide/tantalum oxide/glass (not annealed) and aluminum oxide/vanadium oxide. Non-ordered aluminum oxide is characterized by low transmission (no more than 8%) but has a developed surface and may be of interest for the formation of films with poor adhesion on smooth substrates, for example, photocatalytic active xerogels. The refractive indices of dispersion of the obtained layers were calculated from the transmission spectra by the envelope method. The dispersion of the refractive indices of the obtained oxide films is insignificant in a wide range of wavelengths, and the deviation from the average value is assumed to be observed near the intrinsic absorption edges of the films. The glasses with proposed semi-transparent nanostructured oxide layers are promising substrate structures for subsequent sol–gel coating layers used in photocatalytic purification systems or up-conversion modules of tandem silica solar cells with forward and reverse illumination

Изучение электрокинетических возможностей сепарации и концентрирования бактерий (S.aureus) в цельной крови четырехэлектродным биосенсорным чип-форматом с прозрачными микроэлектродами

The electrokinetic possibilities of separation and concentration of S.aureus bacteria in human whole blood (test mixture) were studied using a new design of a four-electrode biosensor chip format with transparent microelectrodes. In the measurements, a closed cell was used, into which the test mixture was poured. The electrokinetic movement of bacteria during concentration was observed when AC voltage was applied to the first and second annular external electrodes, and DC voltage was applied to the third and fourth semicircular central electrodes. The process of separation of erythrocytes and concentration of bacteria was recorded by an optical method. It is shown that the concentration of bacteria appears after 8 minutes and increases by 30 minutes in the region of the central electrodes under model conditions. The measurements were carried out on two biosensor chip formats having almost identical electrophysical parameters of capacitance and conductivity at frequencies from 100 Hz to 1 MHz. It is determined that the amplitude-frequency mode and biosensor chip format can be used to develop methodological support for the identification of bacterial species, but only by optical methods. It is shown that in order to increase the number of bacteria on both of the central electrode in the concentration mode, it is necessary to increase the speed of the electroosmotic flow at alternating current, by optimizing the composition of the medium and the parameters of the electrical regime in order to equalize the rates of separation and concentration processes.Изучены электрокинетические возможности сепарации и концентрирования бактерий S.aureus в цельной крови человека (исследуемая смесь) с помощью новой конструкции четырехэлектродного биосенсорного чип-формата с прозрачными микроэлектродами. В исследованиях использована закрытая ячейка, в которую заливали исследуемую смесь. Электрокинетическое перемещение бактерий при концентрировании наблюдалось при подаче на первый и второй кольцевые внешние электроды переменного напряжения, а на третий и четвертый полукруглые центральные электроды – постоянного напряжения. Процесс сепарации эритроцитов и концентрирования бактерий фиксировался оптическим методом для модельных условий и в цельной крови. Показано, что концентрирование бактерий проявляется через 8 минут и увеличивается к 30 минуте в области центральных электродов в модельных условиях. Измерения были проведены на биосенсорных чип-форматах, имеющих практически одинаковые электрофизические параметры емкости и проводимости на частотах от 100 Гц до 1 МГц. Установлено, что амплитудно-частотный режим и биосенсорный чип-формат могут быть использованы для разработки методического обеспечения идентификации вида бактерий, но только оптическими методами. Показано, что для увеличения количества бактерий на центральных электродах в режиме концентрирования необходимо повысить скорость электроосмотического потока на переменном токе путем оптимизации состава среды и параметров электрического режима, чтобы уравнять скорости процессов сепарации и концентрирования

ФОТОЛИТОГРАФИЯ НА ПЛЕНОЧНЫХ СТРУКТУРАХ КСЕРОГЕЛЬ/ПОРИСТЫЙ АНОДНЫЙ ОКСИД АЛЮМИНИЯ, СФОРМИРОВАННЫХ В РАЗЛИЧНЫХ ЭЛЕКТРОЛИТАХ

The results of study the morphology of the microstructured porous anodic alumina films formed using electrochemical anodization, sol-gel synthesis, photolithography and chemical etching are given. The metal mask was not used in photolithography, because of fabrication the continuous xerogel film. The perspective of application of these structures in planar optoelectronics and photocatalyses are discussed.Приведены результаты исследования морфологии микроструктурированных пленок пористого анодного оксида алюминия, сформированных с применением электрохимического анодирования, золь-гель синтеза, фотолитографии и химического травления. Для выполнения фотолитографии защитная металлическая маска не использовалась за счет формирования сплошной пленки ксерогеля. Обсуждаются перспективы применения таких структур в планарной оптоэлектронике и фотокатализе