Publications by authors named "Strzhemechny Y"

As antibiotic resistance increases and antibiotic development dwindles, new antimicrobial agents are needed. Recent advances in nanoscale engineering have increased interest in metal oxide nanoparticles, particularly zinc oxide nanoparticles, as antimicrobial agents. Zinc oxide nanoparticles are promising due to their broad-spectrum antibacterial activity and low production cost.

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The cubic zirconia (ZrO) is attractive for a broad range of applications. However, at room temperature, the cubic phase needs to be stabilized. The most studied stabilization method is the addition of the oxides of trivalent metals, such as ScO.

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Nano- and microscale zinc oxide (ZnO) exhibits significant potential as a novel antibacterial agent in biomedical applications. However, the uncertainty regarding the underlying mechanisms of the observed antimicrobial action inhibits the realization of this potential. Particularly, the nature of interactions at the free crystalline surface and the influence of the local bacterial environment remains unclear.

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We studied room temperature phosphorescence of tryptophan (TRP) embedded in poly (vinyl alcohol) films. With UV (285 nm) excitation, the phosphorescence spectrum of tryptophan appears at about 460 nm. We also observed the TRP phosphorescence with blue light excitation at 410 nm, well outside of the S→Sabsorption.

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Nano- and microcrystalline ZnO is an inexpensive, easily synthesized material with a multitude of applications. Its usefulness in the present and future stems from its exceptional optoelectronic, structural, and chemical characteristics as well as a broad range of production techniques. One application comes from its ability to inhibit bacterial growth.

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A fluorescence lifetime imaging probe with a long lifetime was used in combination with time-gating for the detection of hyaluronidase using hyaluronic acid as the probe template. This probe was developed by heavily labeling hyaluronic acid with long lifetime azadioxatriangulenium fluorophores (ADOTA). We used this probe to image hyaluronidase produced by DU-145 prostate cancer cells.

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We present optical studies of two different size distributions of silver triangular nanoprisms, one with a dipole resonance at 520 nm and the other with a dipole resonance at 650 nm, placed in different media. Significant wavelength-dependent depolarization of scattered light from the silver nanoprisms suspended in water indicates strong interference of multiple surface plasmon resonant modes in the same particle. We use this depolarization as a probe of light scattering by the nanoprisms in a lipid solution due to the rejection of a polarized background scattering.

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Unlabelled: Mesoporous silicon and porous silicon/Ni nanocomposites have been investigated in this work employing light-dark surface photovoltage (SPV) transients to monitor the response of surface charge dynamics to illumination changes. The samples were prepared by anodization of a highly n-doped silicon wafer and a subsequent electrodepositing of Ni into the pores. The resulting pores were oriented towards the surface with an average pore diameter of 60 nm and the thickness of the porous layer of approximately 40 μm.

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As-received BaTiO₃ nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyl)triethoxysilane (APTES) and mixed with poly(methyl methacrylate)/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.

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Amorphous carbon (a-C) nanoclusters were synthesized by the implantation of carbon ions (C-) into thermally grown silicon dioxide film (-500 nm thick) on a Si (100) wafer and processed by high temperature thermal annealing. The carbon ions were implanted with an energy of 70 keV at a fluence of 5 x 10(17) atoms/cm2. The implanted samples were annealed at 1100 degrees C for different time periods in a gas mixture of 96% Ar+4% H2.

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