Search results for " Nanoparticle"

Plasmonic Nanosensor Array for Multiplexed DNA-based Pathogen Detection

2019

In this research we introduce a plasmonic nanoparticle based optical biosensor for monitoring of molecular binding events. The sensor utilizes spotted gold nanoparticle arrays as sensing platform. The nanoparticle spots are functionalized with capture DNA sequences complementary to the analyte (target) DNA. Upon incubation with the target sequence, it will bind on the respectively complementary functionalized particle spot. This binding changes the local refractive index, which is detected spectroscopically as the resulting changes of the localized surface plasmon resonance (LSPR) peak wavelength. In order to increase the signal, a small gold nanoparticle label is introduced. The binding ca…

Stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles-metal organic framework composite: Determination of N-nitrosamines in…

2019

Abstract A new analytical method based on the recently proposed stir bar sorptive-dispersive microextraction (SBSDME) technique has been developed to determine eight hazardous N-nitrosamines in cosmetic products. As previous step, a simple clean-up is carried out with hexane to remove those highly lipophilic compounds that disturb the SBSDME step. Subsequently, SBSDME is performed by using magnetic nanoparticles–metal organic framework composite, CoFe2O4/MIL-101(Fe), as sorbent to entrap the target analytes, which are later chemically desorbed and measured by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The experimental variables related to the SBSDME procedure were studied to…

The influence of the anatase nanoparticles boundaries on the titania activity performance

2014

Metal oxides structures, formed by ordered self-assembling of crystalline nanoparticles aggregates, are attracting growing attention in fields such as catalysis or solar cells. The properties of these structures are influenced not only by their morphology and nanoparticles composition but also by the assembled particles boundaries. In order to determine the influence of these boundaries on the structures properties, the present investigation has been devoted to study the characteristics of anatase nanoparticles boundaries in titania aggregates prepared by TiCl4 hydrolysis at low temperature. Proton magic angle spinning nuclear magnetic resonance and high resolution transmission electron mic…

Reversible Photodoping of TiO2 Nanoparticles for Photochromic Applications

2018

Financial support from the Estonian Research Council (IUT2-25, IUT2-26, and PUTJD680) is gratefully acknowledged. This work was supported by the Academy of Finland (decision numbers 141481 and 286713) and by the EU through the European Regional Development Fund (Center of Excellence for Zero Energy and Resource Efficient Smart Buildings and Districts-ZEBE, 2014-2020.4.01.15-0016). Work is supported by the Latvian Academy of Sciences in the framework of FLPP (Plasmonic oxide quantum dots for energy saving smart windows, lzp-2018/1-0187).

Nanostructured Pt–TiO2 composite thin films obtained by direct liquid injection metal organic chemical vapor deposition: Control of chemical state by…

2015

Abstract Nanostructured Pt–TiO 2 composite thin films were synthesized by direct liquid injection metal organic chemical vapor deposition process, using trimethyl(methylcyclopentadienyl)platinum and titanium isopropoxide as precursors. Surface and cross-sectional morphologies obtained by scanning electron microscopy and transmission electron microscopy evidenced the uniform distribution of platinum nanoparticles in the TiO 2 matrix. At higher Pt content, the X-ray diffraction analysis showed that the face-centered cubic phase of platinum appeared together with an anatase TiO 2 structure. In addition, as far as the platinum chemical state is concerned, the co-deposition of TiO 2 and Pt allow…

Antimicrobial activity of biogenically produced spherical Se-nanomaterials embedded in organic material against Pseudomonas aeruginosa and Staphyloco…

2017

In an effort to prevent the formation of pathogenic biofilms on hydroxyapatite (HA)-based clinical devices and surfaces, we present a study evaluating the antimicrobial efficacy of Spherical biogenic Se-Nanostructures Embedded in Organic material (Bio Se-NEMO-S) produced by Bacillus mycoides SelTE01 in comparison with two different chemical selenium nanoparticle (SeNP) classes. These nanomaterials have been studied as potential antimicrobials for eradication of established HA-grown biofilms, for preventing biofilm formation on HA-coated surfaces and for inhibition of planktonic cell growth of Pseudomonas aeruginosa NCTC 12934 and Staphylococcus aureus ATCC 25923. Bio Se-NEMO resulted more e…

Antibacterial and white spot lesions preventive effect of an orthodontic resin modified with silver-nanoparticles

2021

Background To evaluate the antibacterial property of a modified orthodontic resin with different concentrations of silver-nanoparticles (AgNPs), and quantify its preventive effect on the formation of white spot lesions (WSLs). Material and Methods An orthodontic resin (Transbond XT) was modified with four concentrations of AgNPs (1%, 0.5%, 0.1%, and 0.05%), the orthodontic resin without AgNPs was used as control. Polymerized resin discs (n=80) were submitted to Agar diffusion test on Petri dishes inoculated with Streptococcus mutans and Lactobacillus acidophilus. In addition, resin discs of each group (n=40) were placed in 96-well plates with bacterial suspensions to evaluate the colony-for…

Bacterial metal nanoparticles to develop new weapons against bacterial biofilms and infections

2021

The widespread use of antibiotics has resulted in the outbreak and spread of antibiotic-resistant pathogens. Bacterial antibiotic resistance may develop at cellular and community levels. In the latter case, it is based on tolerance which implicates the shift from a free-living form of life (i.e., planktonic) to a sessile multi-stratified community (i.e., biofilm). Metal nanoparticles (MNPs) have been shown to be promising candidates as antimicrobial agents. MNPs are able to interact with and penetrate bacterial biofilms, thus, resulting effective antibiofilm compounds. Another interesting aspect is the possibility of using plants, fungi, yeasts, and bacteria to obtain biogenic MNPs (BMNP). …

Synergistic effect with antibiotics and inhibition of bacterial biofilm formation by polyaminocyclodextrin-silver nanoparticles

2018

Plant extracts as green reductants for the synthesis of silver nanoparticles: lessons from chemical synthesis.

2018

The increasing use of silver (Ag) nanoparticles (NPs) in daily-life applications, electronics, or catalysis calls for green and cost-efficient synthetic methods. Ag NPs are used especially in biomedicine because of their antibacterial, antifungal, or anticancer properties. Chemical synthesis allows tuning the particle morphology, size, and crystallinity, but requires toxic and hazardous chemicals. Bioinspired synthetic protocols have shown promise to minimize environmental impact, but biological protocols for the synthesis of Ag NPs lack control on the morphology and crystallinity. This review briefly compiles the chemical synthesis of Ag NPs and contrasts it with "green" protocols based on…