scholarly journals Synthesis, properties and functionalization of gold nanostars for medical diagnostics

2021 ◽  
pp. 97-99
Author(s):  
T.E. Smoliarova ◽  
Keyword(s):  
Medical Diagnostics ◽  
Colloidal Synthesis ◽  
Seed Solution ◽  
Gold Nanostars ◽  
Transmission Electron ◽  
Highly Sensitive ◽  
Synthesis Properties ◽  
Microscopy Analysis ◽  
Triton X ◽  
Synthesis Approach

Th e aim of the research. To evaluate two approaches to colloidal synthesis using two diff erent non-toxic surfactants (PVP and Triton X-100) and their properties for future use. Material and methods. (PVP) Th e solution of GNSs with short tips was prepared in 200 ml vial. 20 mg of PVP (Polyvinylpyrrolidone, 1-ethenylpyrrolidin-2-one) were dissolved in the 200 mL of DMF (N,N-Dimethylmethanamide) (with the sonication to dissolve well). (Triton X-100) In a typical preparation of GNSs with long tips, the seed solution was prepared in a 20mL vial: 5mL of HAuCl4 5∙10-4M in water are added to 5mL of an aqueous solution of TritonX-100 0.1M. To examinate the shape and properties of prepared gold nanostars Cary 100 Bio Spectrophotometer using quartz cuvettes was used to taken on UV-Vis spectra. Transmission Electron Microscopy (TEM) was used to obtain shape and size of prepared GNSs. Results. Microscopy analysis shows that the obtained GNSs have completely diff erent shapes. Th e GNSs fabricated using synthesis approach with PVP have shorter tips and the cores are larger than the GNSs synthesized with Triton X-100 synthesis approach. TEM-images of the second ones show smaller size nanoparticles with the longer and thinner tips. Optical properties of the synthesized GNSs were analyzed using UV-vis-NIR absorbtion spectra, which shows maximum plasmon existence at 800 nm for GNSs synthesized with PVP and at 850 nm for GNSs synthesized with Triton X-100. Conclusion. In summary, we developed GNSs using two colloidal synthesis approaches with the use of two diff erent non-toxic surfactants (PVP and Triton X-100). In the future, gold nanostars are planned to be used to develop highly sensitive methods of medical diagnostics.

State-of-art of silver and gold nanoparticles synthesis routes, characterization and applications: a review

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Faisal Ali ◽  
Muhammad Hamza ◽  
Munawar Iqbal ◽  
Beriham Basha ◽  
Norah Alwadai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
X Rays ◽  
Ag Nps ◽  
Au Nps ◽  
Advantages And Disadvantages ◽  
Transmission Electron ◽  
Synthesis Properties ◽  
Synthesis Routes ◽  
Synthesis Approach ◽  
Comprehensive Study

Abstract To date, the noble metal-based nanoparticles have been used in every field of life. The Au and Ag nanoparticles (NPs) have been fabricated employing different techniques to tune the properties. In this study, the methodologies developed and adopted for the fabrication of Au and Ag have been discussed, which include physical, chemical and biological routes. The Au and Ag characteristics (morphology, size, shape) along with advantages and disadvantages are discussed. The Au and Ag NPs catalytic and biomedical applications are discussed. For the Ag and Au NPs characterization, SEM (scanning electron microscope), TEM (transmission electron microscope), FTIR (Fourier transform infra-red spectroscopy), XRD (X-rays diffraction) and DLS (dynamic light scattering) techniques are employed. The properties of Au and Ag NPs found dependent to synthesis approach, i.e., the size, shape and morphologies, which showed a promising Catalytic, drug delivery and antimicrobial agent applications. The review is a comprehensive study for the comparison of Au and Ag NPs synthesis, properties and applications in different fields.

scholarly journals Epithelial structure revealed by chemical dissection and unembedded electron microscopy.

1984 ◽  
Vol 99 (1) ◽  
pp. 203s-208s ◽  
Author(s):  
E G Fey ◽  
D G Capco ◽  
G Krochmalnic ◽  
S Penman
Keyword(s):  
Nuclear Matrix ◽  
Intermediate Filament ◽  
Protein Composition ◽  
Intact Cells ◽  
Thin Sections ◽  
Transmission Electron ◽  
Kidney Epithelial Cell ◽  
Epithelial Structure ◽  
Triton X ◽  
Whole Mounts

Cytoskeletal structures obtained after extraction of Madin-Darby canine kidney epithelial cell monolayers with Triton X-100 were examined in transmission electron micrographs of cell whole mounts and unembedded thick sections. The cytoskeleton, an ordered structure consisting of a peripheral plasma lamina, a complex network of filaments, and chromatin-containing nuclei, was revealed after extraction of intact cells with a nearly physiological buffer containing Triton X-100. The cytoskeleton was further fractionated by extraction with (NH4)2SO4, which left a structure enriched in intermediate filaments and desmosomes around the nuclei. A further digestion with nuclease and elution with (NH4)2SO4 removed the chromatin. The stable structure that remained after this procedure retained much of the epithelial morphology and contained essentially all of the cytokeratin filaments and desmosomes and the chromatin-depleted nuclear matrices. This structural network may serve as a scaffold for epithelial organization. The cytoskeleton and the underlying nuclear matrix intermediate filament scaffold, when examined in both conventional embedded thin sections and in unembedded whole mounts and thick sections, showed the retention of many of the detailed morphological aspects of the intact cells, which suggests a structural continuum linking the nuclear matrix, the intermediate filament network, and the intercellular desmosomal junctions. Most importantly, the protein composition of each of the four fractions obtained by this sequential procedure was essentially unique. Thus, the proteins constituting the soluble fraction, the cytoskeleton, the chromatin fraction, and the underlying nuclear matrix-intermediate filament scaffold are biochemically distinct.

scholarly journals Adhesion of cells to surfaces coated with polylysine. Applications to electron microscopy.

1975 ◽  
Vol 66 (1) ◽  
pp. 198-200 ◽  
Author(s):  
D Mazia ◽  
G Schatten ◽  
W Sale
Keyword(s):  
Electron Microscopy ◽  
Sea Urchin ◽  
Mammalian Cells ◽  
Experimental Treatment ◽  
The Body ◽  
Transmission Electron ◽  
Coated Plate ◽  
Living Material ◽  
Coated Surfaces ◽  
Triton X

Cells of many kinds adhere firmly to glass or plastic surfaces which have been pretreated with polylysine. The attachment takes place as soon as the cells make contact with the surfaces, and the flattening of the cells against the surfaces is quite rapid. Cells which do not normally adhere to solid surfaces, such as sea urchin eggs, attach as well as cells which normally do so, such as amebas or mammalian cells in culture. The adhesion is interpreted simply as the interaction between the polyanionic cell surfaces and the polycationic layer of adsorbed polylysine. The attachment of cells to the polylysine-treated surfaces can be exploited for a variety of experimental manipulations. In the preparation of samples for scanning or transmission electron microscopy, the living material may first be attached to a polylysine-coated plate or grid, subjected to some experimental treatment (fertilization of an egg, for example), then transferred rapidly to fixative and further passed through processing for observation; each step involves only the transfer of the plate or grid from one container to the next. The cells are not detached. The adhesion of the cell may be so firm that the body of the cell may be sheared away, leaving attached a patch of cell surface, face up, for observation of its inner aspect. For example, one may observe secretory vesicles on the inner face of the surface (3) or may study the association of filaments with the inner surface (Fig. 1). Subcellular structures may attach to the polylysine-coated surfaces. So far, we have found this to be the case for nuclei isolated from sea urchin embryos and for the microtubules of flagella, which are well displayed after the membrane has been disrupted by Triton X-100 (Fig. 2).

scholarly journals Thermodynamic Modelling and Microstructural Study of Z-Phase Formation in a Ta-Alloyed Martensitic Steel

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1332
Author(s):  
Florian Riedlsperger ◽  
Bernadette Gsellmann ◽  
Erwin Povoden-Karadeniz ◽  
Oriana Tassa ◽  
Susanna Matera ◽  
...  
Keyword(s):  
Special Focus ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Computational Framework ◽  
Mobility Data ◽  
Interfacial Energies ◽  
Transmission Electron ◽  
Size Number ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

A thermokinetic computational framework for precipitate transformation simulations in Ta-containing martensitic Z-steels was developed, including Calphad thermodynamics, diffusion mobility data from the literature, and a kinetic parameter setup that considered precipitation sites, interfacial energies and dislocation density evolution. The thermodynamics of Ta-containing subsystems were assessed by atomic solubility data and enthalpies from the literature as well as from the experimental dissolution temperature of Ta-based Z-phase CrTaN obtained from differential scanning calorimetry. Accompanied by a comprehensive transmission electron microscopy analysis of the microstructure, thermokinetic precipitation simulations with a wide-ranging and well-documented set of input parameters were carried out in MatCalc for one sample alloy. A special focus was placed on modelling the transformation of MX into the Z-phase, which was driven by Cr diffusion. The simulation results showed excellent agreement with experimental data in regard to size, number density and chemical composition of the precipitates, showing the usability of the developed thermokinetic simulation framework.

Optimization of Green Synthesis Approach of Silver Nanoparticles Using Indonesian Wild Honey

2021 ◽  
Vol 891 ◽  
pp. 111-115
Author(s):  
Maradhana Agung Marsudi ◽  
Farah Fitria Sari ◽  
Pandu Mauliddin Wicaksono ◽  
Adinda Asmoro ◽  
Arif Basuki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Count ◽  
Transmission Electron ◽  
Nitrate Precursor ◽  
Synthesis Approach

In this work, silver nanoparticles have been successfully synthesized using simple and environmentally friendly ‘green synthesis’ method using Indonesian wild honey as mediator. Particle count and size can be optimized by varying the silver nitrate precursor and honey concentration, with the help of sodium hydroxide as pH regulator. Based on X-ray diffraction (XRD) result, crystalline structure of Ag has been confirmed in sample with impurities from AgCl. Based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, it was found that the smallest average particles size of AgNPs (117.5 nm from DLS and 11.1 nm from TEM) was obtained at sample with 5% w/v of honey and 0.5 mM of AgNO3.

scholarly journals Immunosensor Based on Long-Period Fiber Gratings for Detection of Viruses Causing Gastroenteritis

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 813 ◽  
Author(s):  
Marta Janczuk-Richter ◽  
Beata Gromadzka ◽  
Łukasz Richter ◽  
Mirosława Panasiuk ◽  
Karolina Zimmer ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Medical Diagnostics ◽  
Label Free ◽  
Fiber Gratings ◽  
Fast Detection ◽  
Long Period ◽  
Highly Sensitive ◽  
Protein Receptors ◽  
Long Period Fiber Gratings ◽  
Vaccine Testing

Since the norovirus is the main cause of acute gastroenteritis all over the world, its fast detection is crucial in medical diagnostics. In this work, a rapid, sensitive, and selective optical fiber biosensor for the detection of norovirus virus-like particles (VLPs) is reported. The sensor is based on highly sensitive long-period fiber gratings (LPFGs) coated with antibodies against the main coat protein of the norovirus. Several modification methods were verified to obtain reliable immobilization of protein receptors on the LPFG surface. We were able to detect 1 ng/mL norovirus VLPs in a 40-min assay in a label-free manner. Thanks to the application of an optical fiber as the sensor, there is a possibility to increase the user’s safety by separating the measurement point from the signal processing setup. Moreover, our sensor is small and light, and the proposed assay is straightforward. The designed LPFG-based biosensor could be applied in both fast norovirus detection and in vaccine testing.

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