In this work, the photoluminescence spectra (PL) of porous silicon (PS) have been modified by adding gold nanoparticles (AuNPs) to PS layer. PS was produced via Photo electro-chemical etching (PECE) method of n-type Si wafer with resistivity of about (10 Ω.cm) and (100) orientation. Laser wavelength of (630 nm) and illumination intensity of about (30 mW/cm2), etching current density of (10mA/cm2), and etching time of (4 min) were used during the etching process. The bare PS before metallic deposition process and porous silicon/gold nanoparticles (PS/AuNPs) structures were investigated by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-Ray (EDX). The photoluminescence spectra were investigated as a function of gold nanoparticles sizes and distribution on the surface of PS.
It was found that there are two behaviours were observed for the photoluminescence spectra of PS/AuNPs substrate; quenching and enhancement effects based on the average gold nanoparticles sizes and their aggregation forms.
Acinetobacter baumannii is highly adapted to hospital environments, causing persistent chronic infections due to its ability to form biofilms. In this work, the antibiofilm activity of AuNPs with a subMIC concentration of 9.34 μg/ml was investigated by the microtiter plate method against 80 clinical isolates of A. baumannii. The results revealed that the biofilm was significantly (P< 0.05) reduced by 48.2 – 82.1%.
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Biocompatible gold nanoparticles were successfully synthesized by hibiscus plant leaf extract as a bioreactor. The prepared nanoparticles were evaluated using UV/Vis spectroscopy, Atomic Force Microscopy (AFM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction and Scanning Electron Microscopy (SEM) . The study also investigated the effect of the different gamma irradiation doses on the size and dispersion of the produced nanoparticles. In UV- Vis spectra, the peak of Au NPs' surface plasmon resonance (SPR) was detected as a single peak at 543 nm. The gamma irradiation induced a blue shift in the SPR peak, which indicates that it might be applied as affective factor for size control. Physical as well as chemi
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In this work, biocompatible gold nanoparticles were synthesized by reducing the chloroauric acid with ascorbic acid as a reducing agent. Colloidal gold nanoparticles were stabilized through nontoxic acacia gum sodium hydroxide .Synthesizing gold nano particle is confirmed by the change in color of chloroauric acid from yellow to ruby red and brown color depending on the stabilizers. The gold nanoparticles were characterized by UV-Visible spectrophotometer. Where the peak of the absorbance of surface plasmon resonance (SPR) was observed between the wave length 526 and 535 nm. The results of zeta potential were found in rang (-19, -40 mv), AFM and TEM images show two different shapes, hexagonal and spherical and the size of gold nanopartic
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Background: The mechanical and physical properties of Polymethyl methacrylate (PMMA) don’tfulfill the entire ideal requirements of denture base materials. The purpose of this study was to produce new modified polymer nanocomposite (PMMA /ZrO2-TiO2) andassess itsimpact strength, transverse strength and thermal conductivity in comparison to the conventionalheat polymerized acrylic resin. Materials and Methods: Both ZrO2 and TiO2nano fillers were silanized with TMSPM (trimethoxysilyl propyl methacrylate) silane coupling agent before beingdispersed by ultrasonication with the methylmethacrylate (monomer) and mixed with the polymer by means of 2% by weight in (1:1) ratio, 60 specimens were constructed by conventional water bath processing
... Show MoreIn this work, yttrium oxide particles (powder) reinforced AL-Si matrix composites (Y2O3/Al-Si) and Chromium oxide particles reinforced AL-Si matrix composites (Cr2O3/AL-Si) were prepared by direct squeeze casting. The volume percentages of yttrium oxide used are (4, 8.1, 12.1, 16.1 vol %) and the volume percentages of the chromium oxide particles used are (3.1, 6.3, 9.4, 12.5 vol. %). The parameters affecting the preparation of Y2O3/Al-Si and Cr2O3/AL-Si composites by direct squeeze casting process were studied. The molten Al-Si alloy with yttrium oxide particles or with chromium oxide particles was stirred again using an electrical stirrer at speed 500 rpm and the molten alloy was poured into the squeeze die cavity. Th
... Show MoreIn this work, the antibacterial effectiveness of face masks made from polypropylene, against Candida albicans and Pseudomonas aeruginosa pathogenic was improved by soaking in gold nanoparticles suspension prepared by a one-step precipitation method. The fabricated nanoparticles at different concentrations were characterized by UV-visible absorption and showed a broad surface Plasmon band at around 520 nm. The FE-SEM images showed the polypropylene fibres highly attached with the spherical AuNPs of diameters around 25 nm over the surfaces of the soaked fibres. The Fourier Transform Infrared Spectroscopy (FTIR) of pure and treated face masks in AuNPs conform to the characteristics bands for the polypropylene bands. There are some differences
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Background In recent years, there has been a notable increase in the level of attention devoted to exploring capabilities of nanoparticles, specifically gold nanoparticles AuNPs, within context of modern times. AuNPs possess distinct biophysical properties, as a novel avenue as an antibacterial agent targeting Streptococcus Mutans and Candida Albicans. The aim of this study to create a nano-platform that has the potential to be environmentally sustainable, in addition to exhibiting exceptional antimicrobial properties against Streptococcus Mutans as well as Candida Albicans. Methods this study involved utilization of
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Background: In this study, a targeted drug delivery system has been developed based on nanoporous particles covered with cadmium sulfide and loaded with 5-flourouracil. The nanoparticles loaded drug exerts a cooperative antineoplastic activity.
Results: The development of nanoparticles loaded anticancer agent for possible application in targeted treatment of cancer where the drug release is triggered by externally applied UV irradiation. In addition, the treatment of cancer cells with drug loaded magnetic material leads to a decrease in viability of the cells due to the activity of cadmium nanoparticles. Upon exposure to low power UV light (365 nm) the loaded 5-flourouracil is released which indu
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Pulsed laser ablation in liquid (PLAL) technique can produce high purity nanoparticles, it is a top-down physical method based on the principle of dividing metal ion bulk precursors into metal atoms, this method was used in this work to synthesis cobalt nanoparticals (CoPNs) with the use of Nd: YAG laser with two wavelengths (355 nm) and (532 nm) at energies (500 mJ) and (600 mJ) respectively, with number of pulses (1000,1100, 1200, 1300, and 1400) for each wavelength. The properties of the prepared nanoparticles were studied by UV-Vis, XRD, SEM with EDX, AFM, and FTIR analysis and then its antibacterial activity was studied by applying it on two types of bacteria with gram-positive (Staphylococcus aureus, Streptococc
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The synthesis of gold nanoparticles AuNPs was achievedby the reduction of sodium tetrachloroaurate (III) (NaAuCl4) with ceftriaxone sodium (CR) in aqueous solutionswithout the use of other reducing agent. The effect of reactants concentration, temperature and pH on the sizes and morphology of AuNPs were also studied. The synthesized AuNPs were characterized by UV- visible spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscope (AFM) analysis. Conjugation of antibiotic with the nanoparticles was characterized by FTIR spectrophotometry.