Integrating more than one type of metal into a nanoparticle that has a well-defined morphology and composition expands the functionalities of nanocatalysts. For a metal core/porous multimetallic shell nanoparticle, the availability of catalytically active surface sites and molecular mass transport can be enhanced, and the multielemental synergy can facilitate intraparticle charge transport. In this work, a reliable and robust synthesis of such a functional tetrametallic nanoparticle type is presented, where a micro- and mesoporous PdPtIr shell is grown on Au nanorods.
View Article and Find Full Text PDFIn this paper, we report a multiscale investigation of the compositional, morphological, structural, electrical, and optical emission properties of 2H-MoS obtained by sulfurization at 800 °C of very thin MoO films (with thickness ranging from ~2.8 nm to ~4.2 nm) on a SiO/Si substrate.
View Article and Find Full Text PDFNanostructured photoactive systems are promising for applications such as air and water purification, including self-cleaning coatings. In this study, mesoporous TiO sol-gel coatings with different pore structures were prepared and modified with silver by two methods: the "mixing" method by adding AgNO to the precursor sol, and the "impregnation" method by immersing the samples in AgNO solution (0.03 and 1 M) followed by heat treatment.
View Article and Find Full Text PDFCross-sectional study of sound primary dental enamel revealed hardness zonation and, in parallel, significant change in the Mg content below the prismless layer. Mg content is known to play an important role in enamel apatite biomineralization, therefore, Mg ion exchange experiments were carried out on the outer surface of sound primary molars and on reference abiogenic Ca-phosphates using MgCl solution. Effects of Mg incorporation on crystal/particle size, ionic ratio and morphology were compared and the observed changes were explained by parallel diffusion and dissolution/reprecipitation processes.
View Article and Find Full Text PDFMicropatterning of living single cells and cell clusters over millimeter-centimeter scale areas is of high demand in the development of cell-based biosensors. Micropatterning methodologies require both a suitable biomimetic support and a printing technology. In this work, we present the micropatterning of living mammalian cells on carboxymethyl dextran (CMD) hydrogel layers using the FluidFM BOT technology.
View Article and Find Full Text PDFSurface coatings of the polysaccharide dextran and its derivatives are key ingredients especially in label-free biosensors for the suppression of non-specific binding and for receptor immobilization. Nevertheless, the nanostructure of these ultrathin coatings and its tailoring by the variation of the preparation conditions have not been profoundly characterized and understood. In this work carboxymethylated dextran (CMD) was prepared and used for fabricating ultrathin surface coatings.
View Article and Find Full Text PDFUnlabelled: Biomimetic coatings with cell-adhesion-regulating functionalities are intensively researched today. For example, cell-based biosensing for drug development, biomedical implants, and tissue engineering require that the surface adhesion of living cells is well controlled. Recently, we have shown that the bacterial flagellar protein, flagellin, adsorbs through its terminal segments to hydrophobic surfaces, forming an oriented monolayer and exposing its variable D3 domain to the solution.
View Article and Find Full Text PDFA new type of titanate nanotube (TNT) coating is investigated for exploitation in biosensor applications. The TNT layers were prepared from stable but additive-free sols without applying any binding compounds. The simple, fast spin-coating process was carried out at room temperature, and resulted in well-formed films around 10nm thick.
View Article and Find Full Text PDFA new Monte Carlo method has been developed for simulating backscattered electron spectra, and this was applied for determining the surface excitation parameter (SEP). The simulation is based on direct tracking of electron trajectories in the solid, taking into account elastic and inelastic events. The elastic scattering cross sections are taken from literature, while inelastic cross section data are obtained by a fitting procedure.
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