Vanadium dioxide (VO) is a phase transition material that undergoes semiconductor-to-metal transition at the temperature of about 68 °C. This extraordinary feature triggered intensive research focused on the controlled synthesis of VO. In this study, we introduce and investigate an original linker- and solvent-free strategy enabling the production of highly porous VO nanoparticle-based films.
View Article and Find Full Text PDFWe report here on the development of tailored plasmonic AgNPs/C:H:N:O plasma polymer nanocomposites for the detection of the pathogenic bacterium Borrelia afzelii, with high selectivity and sensitivity. Silver (Ag) nanoparticles, generated by a gas aggregation source, are incorporated onto a C:H:N:O plasma polymer matrix, which is deposited by magnetron sputtering of a nylon 6.6.
View Article and Find Full Text PDFIn this study, TiCT underwent laser treatment to reshape it, resulting in the formation of a TiO/TiCT heterojunction. The interaction with laser light induced the formation of spherical TiO composed of an anatase-rutile phase on the TiCT surface. Such a heterostructure was loaded over a titania nanotube (TNT) layer, and the surface area was enhanced through immersion in a TiCl solution followed by thermal treatment.
View Article and Find Full Text PDFThis study investigates the impact of plasma-seed interaction on germination and early plant development, focusing on and . The investigation delves into changes in chemical composition, water absorption, and surface morphology induced by plasma filaments generated in synthetic air. These analyses were conducted using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS).
View Article and Find Full Text PDFRaman spectroscopy is one of the most used biodetection techniques. However, its usability is hampered in the case of low concentrated substances because of the weak intensity of the Raman signal. To overcome this limitation, the use of drop coating deposition Raman spectroscopy (DCDRS), in which the liquid samples are allowed to dry into well-defined patterns where the non-volatile solutes are highly concentrated, is appropriate.
View Article and Find Full Text PDFA mechanical time-of-flight filter intended for measurement of velocities of nanoparticles exiting a gas aggregation source has been developed. Several configurations maximizing simplicity, throughput or resolution are suggested and investigated both theoretically and experimentally. It is shown that the data measured using such filters may be easily converted to the real velocity distribution with high precision.
View Article and Find Full Text PDFInfection associated with titanium based implants remains the most serious problem in implant surgery hence it is important to find optimal strategies to prevent infections. In the present study, we investigated the surface properties, antibacterial activity and biocompatibility of nanocomposite coatings based on an amorphous hydrocarbon (a-C:H) film containing copper nanoparticles (CuNPs) deposited on Ti discs via a gas aggregation cluster source. Three different Cu/a-C:H coatings with approximately the same amount of embedded CuNPs with and without barrier a-C:H layer were fabricated.
View Article and Find Full Text PDFOne of the leading causes of failure for any bone implant is implant-associated infections. The implant-bone interface is in fact the crucial site of infection where both the microorganisms and cells compete to populate the newly introduced implant surface. Most of the work dealing with this issue has focused on the design of implant coatings capable of preventing infection while ignoring cell proliferation or vice versa.
View Article and Find Full Text PDFSurface-enhanced fluorescence (SEF) requires the absorption/emission band of the fluorophore, the localized surface plasmon resonance (LSPR) of the nanostructure and the excitation wavelength to fall in the same (or very close) spectral range. In this paper, we monitor the SEF intensity and lifetime dependence of riboflavin (vitamin B2) adsorbed on a spacer-modified Ag substrate with respect to the thickness of the spacer. The substrates were formed by silver nanoislands deposited onto magnetron-sputtered polytetrafluoroethylene (ms-PTFE).
View Article and Find Full Text PDFMagnetron sputtering is a well-known technique that is commonly used for the deposition of thin compact films. However, as was shown in the 1990s, when sputtering is performed at pressures high enough to trigger volume nucleation/condensation of the supersaturated vapor generated by the magnetron, various kinds of nanoparticles may also be produced. This finding gave rise to the rapid development of magnetron-based gas aggregation sources.
View Article and Find Full Text PDFAntibiotics (Basel)
August 2018
Urgent need for innovative and effective antibacterial coatings in different fields seems to have triggered the development of numerous strategies for the production of such materials. As shown in this short overview, plasma based techniques arouse considerable attention that is connected with the possibility to use these techniques for the production of advanced antibacterial Ag/plasma polymer coatings with tailor-made functional properties. In addition, the plasma-based deposition is believed to be well-suited for the production of novel multi-functional or stimuli-responsive antibacterial films.
View Article and Find Full Text PDFAntibacterial materials are of high importance for medicine, and for the production and conservation of food. Among these materials, polymer films with metal nanoparticles (NPs) are of considerable interest for many practical applications. The paper describes a novel approach for the formation of bactericidal polymer thin films (polystyrene in this case), produced by spin-coating, with Ti and Cu NPs deposited from cluster beams.
View Article and Find Full Text PDFOptimization of surface-enhanced Raman scattering (SERS)-based sensors for (bio)analytical applications has received much attention in recent years. For optimum sensitivity, both the nanostructure fabrication process and the choice of the excitation wavelength used with respect to the specific analyte studied are of crucial importance. In this contribution, detailed SERS intensity profiles were measured using gradient nanostructures with the localized surface-plasmon resonance (LSPR) condition varying across the sample length and using riboflavin as the model biomolecule.
View Article and Find Full Text PDFBeilstein J Nanotechnol
September 2017
This contribution reviews plasma polymer nanoparticles produced by gas aggregation cluster sources either via plasma polymerization of volatile monomers or via radio frequency (RF) magnetron sputtering of conventional polymers. The formation of hydrocarbon, fluorocarbon, silicon- and nitrogen-containing plasma polymer nanoparticles as well as core@shell nanoparticles based on plasma polymers is discussed with a focus on the development of novel nanostructured surfaces.
View Article and Find Full Text PDFNanoparticles composed of multiple silver cores and a plasma polymer shell (multicore@shell) were prepared in a single step with a gas aggregation cluster source operating with Ar/hexamethyldisiloxane mixtures and optionally oxygen. The size distribution of the metal inclusions as well as the chemical composition and the thickness of the shells were found to be controlled by the composition of the working gas mixture. Shell matrices ranging from organosilicon plasma polymer to nearly stoichiometric SiO were obtained.
View Article and Find Full Text PDFSilver nanorod arrays prepared by oblique angle deposition (AgOADs) represent versatile, simple and inexpensive substrates for high sensitivity surface enhanced Raman scattering (SERS) applications. Their anisotropic nature suggests that their optical responses such as the SERS signal, the depolarization ratio, reflectivity and ellipsometric parameters critically depend on the states of polarization, nanorod angular arrangement and specific illumination-observation geometry. SERS polarization and angular dependences of AgOADs were measured using methylene blue (MB) molecule.
View Article and Find Full Text PDFEvaporation of a drop of biomolecular solution on a solid surface typically creates a ring-shaped drying pattern, formed by the so-called "coffee ring" effect. The size and shape of the "coffee ring" pattern is strongly dependent on the properties of the surface as well as on the deposited molecular solution or suspension. In this paper, we tested six types of surfaces differing in their physico-chemical surface characteristics (contact angles, wettability and roughness) as well as in the presence or absence of a base metal layer.
View Article and Find Full Text PDFCell behavior depends strongly on the physical and chemical properties of the material surface, for example, its chemistry and topography. The authors have therefore assessed the influence of materials of different chemical composition (i.e.
View Article and Find Full Text PDFA new route for coating various substrates with antifouling polymer layers was developed. It consisted in deposition of an amino-rich adhesion layer by means of RF magnetron sputtering of Nylon 6,6 followed by the well-controlled, surface-initiated atom transfer radical polymerization of antifouling polymer brushes initiated by bromoisobutyrate covalently attached to amino groups present in the adhesion layer. Polymer brushes of hydroxy- and methoxy-capped oligoethyleneglycol methacrylate and carboxybetaine acrylamide were grafted from bromoisobutyrate initiator attached to a 15 nm thick amino-rich adhesion layer deposited on gold, silicon, polypropylene, and titanium-aluminum-vanadium alloy surfaces.
View Article and Find Full Text PDFPlasma treatment of surfaces as a sterilisation or decontamination method is a promising approach to overcome limitations of conventional techniques. The precise characterisation of the employed plasma discharges, the application of sensitive surface diagnostic methods and targeted experiments to separate the effects of different agents, have led to rapid progress in the understanding of different relevant elementary processes. This contribution provides an overview of the most relevant and recent results, which reveal the importance of chemical sputtering as one of the most important processes for the elimination of biological residuals.
View Article and Find Full Text PDFImmune-stimulating microbiological components like lipopolysaccharide (LPS), lipoteichoic acid (LTA) and zymosan bound onto surfaces lead to severe problems when brought in contact with the organism via surgical instruments or implants. We have shown, in recent studies, that it is possible to detect different immune-stimulating components directly on the surface, via an indirect detection method, using human whole-blood and the monocyte reaction to measure the inflammatory mediator release (IL-1beta) by ELISA. With regard to the inactivation of pyrogenic substances, we present a method based on the application of a low-pressure microwave plasma discharge working at low temperatures.
View Article and Find Full Text PDFThe influence of several sterilization processes (autoclaving, gamma-ray irradiation, ethylene oxide exposure and Ar/H(2) low pressure plasma treatment) on the surface chemistry and the bioadhesive properties of thin films (thickness approximately 20 nm) of plasma-polymerized diethylene glycol dimethyl ether has been studied. X-ray photoelectron spectroscopy (XPS) analysis and cell proliferation tests were used to characterize the surfaces. The XPS results revealed in all cases a change in the surface chemistry of the layer after sterilization, whereas the conservation of non-bioadhesive properties of the coating depends on the type of sterilization process.
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