The internal structure of PMETAC brush/gold nanoparticle composites: a neutron and X-ray reflectivity study

2017 ◽  
Vol 19 (45) ◽  
pp. 30636-30646 ◽  
Author(s):  
D. Kesal ◽  
S. Christau ◽  
M. Trapp ◽  
P. Krause ◽  
R. von Klitzing
Keyword(s):  
Gold Nanoparticles ◽  
Internal Structure ◽  
Gold Nanoparticle ◽  
Electrostatic Interaction ◽  
Polymer Brush ◽  
X Ray ◽  
Nanoparticle Composites

The amount and distribution of gold nanoparticles within a polymer brush matrix can be changed by altering the electrostatic interaction between particle–particle as well as particle–brush.

scholarly journals Tandem X-ray absorption spectroscopy and scattering for in situ time-resolved monitoring of gold nanoparticle mechanosynthesis

2020 ◽  
Vol 56 (71) ◽  
pp. 10329-10332 ◽  
Author(s):  
Paulo F. M. de Oliveira ◽  
Adam A. L. Michalchuk ◽  
Ana Guilherme Buzanich ◽  
Ralf Bienert ◽  
Roberto M. Torresi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Absorption Spectroscopy ◽  
Mechanochemical Synthesis ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Absorption

A new tandem approach combines XRD and XANES for time-resolved in situ monitoring of the mechanochemical synthesis of gold nanoparticles.

Nanoparticle dose enhancement of synchrotron radiation in PRESAGE dosimeters

2020 ◽  
Vol 27 (6) ◽  
pp. 1590-1600
Author(s):  
Frank M. Gagliardi ◽  
Rick D. Franich ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Synchrotron Radiation ◽  
Gold Nanoparticle ◽  
Size Dependence ◽  
Absorbed Dose ◽  
Nanoparticle Concentration ◽  
Dose Enhancement ◽  
X Ray ◽  
Bismuth Nanoparticles ◽  
Synchrotron Beam

The physical absorbed dose enhancement by the inclusion of gold and bismuth nanoparticles fabricated into water-equivalent PRESAGE dosimeters was investigated. Nanoparticle-loaded water-equivalent PRESAGE dosimeters were irradiated with superficial, synchrotron and megavoltage X-ray beams. The change in optical density of the dosimeters was measured using UV–Vis spectrophotometry pre- and post-irradiation using a wavelength of 630 nm. Dose enhancement was measured for 5 nm and 50 nm monodispersed gold nanoparticles, 5–50 nm polydispersed bismuth nanoparticles, and 80 nm monodispersed bismuth nanoparticles at concentrations from 0.25 mM to 2 mM. The dose enhancement was highest for the 95.3 keV mean energy synchrotron beam (16–32%) followed by the 150 kVp superficial beam (12–21%) then the 6 MV beam (2–5%). The bismuth nanoparticle-loaded dosimeters produced a larger dose enhancement than the gold nanoparticle-loaded dosimeters in the synchrotron beam for the same concentration. For the superficial and megavoltage beams the dose enhancement was similar for both species of nanoparticles. The dose enhancement increased with nanoparticle concentration in the dosimeters; however, there was no observed nanoparticle size dependence on the dose enhancement.

The Internal Structure of Macroporous Membranes and Transport of Surface-Modified Nanoparticles

2015 ◽  
Vol 21 (4) ◽  
pp. 936-945 ◽  
Author(s):  
Sang J. Lee ◽  
Kiwoong Kim ◽  
Sungsook Ahn
Keyword(s):  
Gold Nanoparticles ◽  
Internal Structure ◽  
Morphological Structure ◽  
Improve Performance ◽  
X Ray ◽  
X Ray Scattering ◽  
Cellulose Acetate Membranes ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

AbstractUnderstanding the morphological structure of membranes is essential to improve performance of membrane-based applications. In this paper, macroporous membranes were investigated and two methods introduced as an alternative for characterization of stereo-structure of the membranes. We combined the use of synchrotron X-ray nanotomography and small-angle X-ray scattering to examine the internal structure of cellulose acetate membranes with studies of the capture of surface-modified gold nanoparticles within these membranes. Finally, the morphological structures of macroporous membranes were visualized and their relationships with penetration tendency of surface-modified gold nanoparticles were explained.

Chiral nematic cellulose–gold nanoparticle composites from mesoporous photonic cellulose

2015 ◽  
Vol 51 (3) ◽  
pp. 530-533 ◽  
Author(s):  
Maik Schlesinger ◽  
Michael Giese ◽  
Lina K. Blusch ◽  
Wadood Y. Hamad ◽  
Mark J. MacLachlan
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Chiroptical Properties ◽  
Chiral Nematic ◽  
Nanoparticle Composites

Nearly monodisperse gold nanoparticles with chiroptical properties are prepared by the in situ reduction of Au3+ inside mesoporous photonic cellulose.

Graphene/gold nanoparticle composites for ultrasensitive and versatile biomarker assay using single-particle inductively-coupled plasma/mass spectrometry

The Analyst ◽  
2020 ◽  
Vol 145 (24) ◽  
pp. 7932-7940
Author(s):  
Yuqian Xing ◽  
Juan Han ◽  
Xu Wu ◽  
David T. Pierce ◽  
Julia Xiaojun Zhao
Keyword(s):  
Mass Spectrometry ◽  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Single Particle ◽  
Inductively Coupled Plasma ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Nanoparticle Composites

An ultrasensitive biomarker assay platform established by monitoring the gold nanoparticles (AuNPs) desorbed away from graphene triggered by the target using single-particle inductively-coupled plasma/mass spectrometry (spICP-MS).

Gold Nanoparticle Internal Structure and Symmetry Probed by Unified Small-Angle X-ray Scattering and X-ray Diffraction Coupled with Molecular Dynamics Analysis

Nano Letters ◽  
2015 ◽  
Vol 15 (9) ◽  
pp. 6088-6094 ◽  
Author(s):  
Blaise Fleury ◽  
Robinson Cortes-Huerto ◽  
Olivier Taché ◽  
Fabienne Testard ◽  
Nicolas Menguy ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Internal Structure ◽  
Gold Nanoparticle ◽  
Small Angle ◽  
Dynamics Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Gold nanoparticle fortified bamboo biochar Nanocomposite

2021 ◽  
Author(s):  
Aditya lawerence Toppo ◽  
Satya Eswari Jujjavarapu
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Low Cost ◽  
Analytical Techniques ◽  
Organic Matrix ◽  
Chloride Salt ◽  
Biological Origin ◽  
Au Nps ◽  
X Ray ◽  
Vis Spectroscopy

Abstract Gold nanoparticles due to their specific properties and function have found uses in the field of engineering to medical sciences. The Gold nanoparticles are always used in conjugation with other chemicals, metals, proteins, and other organic materials. The addition of other conjugates enhances the properties of Gold nanoparticles. As the insertion of metal nanoparticles into an organic matrix effectively increases the specific surface area of such materials, thereby enhancing the desired properties of the material. The term nanocomposite(NCs) is used for material containing an inorganic moiety, with at least one dimension in a nanometre range of 1–100 nm(nanoparticles ) and other materials like metal, ceramics, and polymers. The term “Bionanocomposite" (BNCs)has been assigned to nanocomposites containing a component of biological origin in the mixture. In this work, Bamboo (Bambusa bambos) was used as the organic matrix for the preparation of gold nanoparticle biochar (Au-NPs/BC) nanocomposite. The one-step synthesis approach was used for the treatment of Bamboo with Auric Chloride Salt at room temperature. In addition to the above process, the bamboo was also pyrolyzed at low temperature after treatment, which helped further to reduce the overall cost of the method. This made the method of preparation of the nanocomposite low cost and eco-friendly. Various analytical techniques such as Fourier transform infrared (FT-IR), X‐ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X‐ray spectroscopy (EDS), and UV–Vis spectroscopy methods were used for the characterization of the synthesized nanocomposite. This nanocomposite was used for the preparation of electrodes and its electrical conductivity was tested. In this method, the nanocomposite was prepared in a good amount via a very simple methodology. The characterization revealed the presence of gold in the nanocomposite, which confirms that this method can be used for the preparation of the (Au-NPs/BC) nanocomposite.

scholarly journals Evaluation of dose enhancement with gold nanoparticles in kilovoltage radiotherapy using the new EGS geometry library in Monte Carlo simulation

2021 ◽  
Vol 8 (4) ◽  
pp. 337-345
Author(s):  
Zaynah Sheeraz ◽  
◽  
James C.L. Chow ◽  
◽  
Keyword(s):  
Monte Carlo Simulation ◽  
Gold Nanoparticles ◽  
Monte Carlo ◽  
Gold Nanoparticle ◽  
Particle Method ◽  
Tumour Volume ◽  
Water Mixture ◽  
Nanoparticle Concentration ◽  
Dose Enhancement ◽  
X Ray

<abstract><sec> <title>Purpose</title> <p>This study compared the dose enhancement predicted in kilovoltage gold nanoparticle-enhanced radiotherapy using the newly developed EGS lattice and the typical gold-water mixture method in Monte Carlo simulation. This new method considered the gold nanoparticle-added volume consisting of solid nanoparticles instead of a gold-water mixture. In addition, this particle method is more realistic in simulation.</p> </sec><sec> <title>Methods</title> <p>A heterogeneous phantom containing bone and water was irradiated by the 105 and 220 kVp x-ray beams. Gold nanoparticles were added to the tumour volume with concentration varying from 3–40 mg/mL in the phantom. The dose enhancement ratio (DER), defined as the ratio of dose at the tumour with and without adding gold nanoparticles, was calculated by the gold-water mixture and particle method using Monte Carlo simulation for comparison.</p> </sec><sec> <title>Results</title> <p>It is found that the DER was 1.44–4.71 (105 kVp) and 1.27–2.43 (220 kVp) for the gold nanoparticle concentration range of 3–40 mg/mL, when they were calculated by the gold-water mixture method. The DER was slightly larger and equal to 1.47–4.84 (105 kVp) and 1.29–2.5 (220 kVp) for the same concentration range, when the particle method was used. Moreover, the DER predicted by both methods increased with an increase of nanoparticle concentration, and a decrease of x-ray beam energy.</p> </sec><sec> <title>Conclusion</title> <p>The deviation of DER determined by the particle and gold-water mixture method was insignificant when considering the uncertainty in the calculation of DER (2%) in the nanoparticle concentration range of 3–40 mg/mL. It is therefore concluded that the gold-water mixture method could predict the dose enhancement as accurate as the newly developed particle method.</p> </sec></abstract>

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

Interference of Gold Nanoparticles with In vitro Endotoxin Detection Assays

2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Surface Reactivity ◽  
In Vitro Assays ◽  
Limulus Amebocyte Lysate ◽  
Chromogenic Assay ◽  
Nanoparticle Suspensions ◽  
Endotoxin Contamination ◽  
Factor C

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.

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