Publications by authors named "Alla Tereshchenko"

In this research we have applied sol-gel synthesis for the deposition of tungsten (VI) oxide (WO) layers using two different reductants (ethanol and propanol) and applying different dipping times. WO samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), photoluminescence (PL) and time-resolved photoluminescence decay methods. Photoelectrochemical (PEC) behaviour of synthesized coatings was investigated using cyclic voltammetry in the dark and under illumination.

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In this research a whispering gallery mode (WGM) resonator based on vertically oriented ZnO nanorods, which were formed on silicon surface (silicon/ZnO-NRs), has been applied in the design of optical immunosensor that was dedicated for the determination of grapevine virus A-type (GVA) proteins. Vertically oriented ZnO-NRs were grown on silicon substrates by atmospheric pressure metal organic chemical vapor deposition (APMOCVD) and the silicon/ZnO-NRs structures formed were characterized by structural and optical methods. Optical characterization demonstrates that silicon/ZnO-NRs-based structures can act as 'whispering gallery mode' (WGM) resonator where quasi-whispering gallery modes (quasi-WGMs) are generated.

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The modelling of protein-protein binding kinetics is important for the development of affinity-sensors and the prediction of signaling protein based drug efficiency. Therefore, in this research we have evaluated the binding kinetics of several genetically designed protein models: (i) three different ligands based on granulocyte colony-stimulating factor GCSF homo-dimeric derivatives linked by differed by linkers of different length and flexibility; (ii) an antibody-like receptor (GCSF-R) based on two GCSF-receptor sites immobilized to Fc domains, which are common parts of protein structures forming antibodies. Genetically engineered GCSF-R is similar to an antibody because it, like the antibody, has two binding sites, which both selectively bind with GCSF ligands.

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In this research we report the gas-sensing properties of TiO/TiO-based hetero-structure, which was 'self-heated' by current that at constant potential passed through the structure. Amperometric measurements were applied for the evaluation of sensor response towards ethanol, methanol, n-propanol and acetone gases/vapours. The sensitivity towards these gases was based on electrical resistance changes, which were determined by amperometric measurements of current at fixed voltage applied between Pt-based contacts/electrodes deposited on the TiO/TiO-based layer.

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In this research, a 9,10-phenanthrenequinone (PQ) was electrochemically polymerized on a graphite rod electrode using potential cycling. The electrode modified by poly-9,10-phenanthrenequinone (poly-PQ) was studied by means of cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy and scanning electron microscopy. The poly-PQ shows variations in growth pattern depending on the number of potential cycles for the initiation of polymerization.

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In this research a mechanism of interaction between a semiconducting TiO layer and bovine leukemia virus protein 51, applied in the design of photoluminescence-based immunosensors, is proposed and discussed. Protein 51 was adsorbed on the surface of a nanostructured TiO thin film, formed on glass substrates (TiO/glass). A photoluminescence (PL) peak shift from 517 nm to 499 nm was observed after modification of the TiO/glass by adsorbed 51 (51/TiO/glass).

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Novel sensitive optical biosensor for determination of Grapevine virus A-type (GVA) proteins (GVA-antigens) has been designed. This biosensor was based on thin films of Zinc Oxide (ZnO) deposited by atomic layer deposition (ALD). The ZnO-based films have demonstrated favorable surface-structural properties for the direct immobilization of antibodies against GVA-antigens in order to form a biosensitive layer sensitive to GVA-antigens.

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