Gold nanoparticles immobilised in a superabsorbent hydrogel matrix: facile synthesis and application for the catalytic reduction of toxic compounds

2020 ◽  
Vol 56 (8) ◽  
pp. 1263-1266 ◽  
Author(s):  
Hassan A. H. Alzahrani ◽  
Mark A. Buckingham ◽  
William P. Wardley ◽  
Richard D. Tilley ◽  
Nicholas Ariotti ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Ionic Strength ◽  
Catalytic Reduction ◽  
High Ionic Strength ◽  
Facile Synthesis ◽  
Superabsorbent Hydrogel ◽  
Toxic Compounds ◽  
Hydrogel Matrix ◽  
Catalytically Active

AuNP easily synthesised inside bulk hydrogel spheres; stable and catalytically active, even in high ionic strength environments.

Patterning gold nanoparticles in liquid environment with high ionic strength for local fabrication of up to 100μm long metallic interconnections

2015 ◽  
Vol 26 (17) ◽  
pp. 175301 ◽  
Author(s):  
Robert R Grüter ◽  
Bernd Dielacher ◽  
Luca Hirt ◽  
János Vörös ◽  
Tomaso Zambelli
Keyword(s):  
Gold Nanoparticles ◽  
Ionic Strength ◽  
High Ionic Strength ◽  
Liquid Environment

scholarly journals Glucomannan-mediated facile synthesis of gold nanoparticles for catalytic reduction of 4-nitrophenol

2014 ◽  
Vol 9 (1) ◽  
pp. 404 ◽  
Author(s):  
Zhao Gao ◽  
Rongxin Su ◽  
Renliang Huang ◽  
Wei Qi ◽  
Zhimin He
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Reduction ◽  
Facile Synthesis

Kinetics and mechanism of the chromium(vi) catalyzed decomposition of hypochlorous acid at elevated temperature and high ionic strength

2018 ◽  
Vol 47 (11) ◽  
pp. 3831-3840 ◽  
Author(s):  
József Kalmár ◽  
Mária Szabó ◽  
Nina Simic ◽  
István Fábián
Keyword(s):  
Elevated Temperature ◽  
Ionic Strength ◽  
Kinetic Model ◽  
Hypochlorous Acid ◽  
Active Form ◽  
High Ionic Strength ◽  
Kinetics And Mechanism ◽  
Chromium Vi ◽  
Catalytically Active ◽  
Detailed Kinetic Model

The decomposition of hypochlorous acid was studied under industrially relevant conditions (6.0 M NaClO3, 80 °C). Chromium(vi) catalyzes the decomposition and the catalytically active form is CrO42−. A detailed kinetic model is proposed for the process.

scholarly journals Study of the Stability of Functionalized Gold Nanoparticles for the Colorimetric Detection of Dipeptidyl Peptidase IV

2018 ◽  
Vol 8 (12) ◽  
pp. 2589 ◽  
Author(s):  
Hasan Aldewachi ◽  
Nicola Woodroofe ◽  
Philip Gardiner
Keyword(s):  
Gold Nanoparticles ◽  
Ionic Strength ◽  
Biomedical Applications ◽  
Colorimetric Detection ◽  
Dipeptidyl Peptidase ◽  
High Ionic Strength ◽  
Dipeptidyl Peptidase Iv ◽  
Au Nps ◽  
Dpp Iv ◽  
The Stability

In this report, we investigated three stabilization strategies of gold nanoparticles and their practical application for the visual detection of dipeptidyl peptidase IV (DPP-IV). Citrate-capped gold nanoparticles (Au NPs) are generally unstable in high-ionic-strength samples. Au NPs are easily tagged with various proteins and biomolecules rich in amino acids, leading to important biomedical applications including targeted drug delivery, cellular imaging, and biosensing. The investigated assays were based on different modes of stabilization, such as the incorporation of polyethylene glycol (PEG) groups, stabilizer peptide, and bifunctionalization. Although all approaches provided highly stable Au NP platforms demonstrated by zeta potential measurements and resistance to aggregation in a high-ionic-strength saline solution, we found that the Au NPs modified with a separate stabilizer ligand provided the highest stability and was the only platform that demonstrated sensitivity to the addition of DPP-IV, whilst PEGylated and peptide-stabilized Au NPs showed no significant response.

Importance of Protease Inhibition in Studies on Purified Factor VIII (Antihaemophilic Factor)

1976 ◽  
Vol 35 (01) ◽  
pp. 186-190 ◽  
Author(s):  
Eugen A. Beck ◽  
Peter Bachmann ◽  
Peter Barbier ◽  
Miha Furlan
Keyword(s):  
Ionic Strength ◽  
Factor Viii ◽  
Gel Filtration ◽  
High Ionic Strength ◽  
Procoagulant Activity ◽  
Carrier Protein ◽  
Protease Inhibition ◽  
Functional Sites ◽  
Molecular Weight Peak ◽  
Von Willebrand

SummaryAccording to some authors factor VIII procoagulant activity may be dissociable from carrier protein (MW~ 2 × 106) by agarose gel filtration, e.g. at high ionic strength. We were able to reproduce this phenomenon. However, addition of protease inhibitor (Trasylol) prevented the appearance of low molecular weight peak of factor VIII procoagulant activity both at high ionic strength and elevated temperature (37°C). We conclude from our results that procoagulant activity and carrier protein (von Willebrand factor, factor VIII antigen) are closely associated functional sites of native factor VIII macro molecule. Consequently, proteolytic degradation should be avoided in functional and structural studies on factor VIII and especially in preparing factor VIII concentrate for therapeutic use.

THE RELATIVE DISTRIBUTION OF THYROXINE, TRIIODOTHYRONINE AND 3,3′,5′-(REVERSE)-TRIIODOTHYRONINE IN VARIOUS FRACTIONS OF THYROGLOBULIN

1978 ◽  
Vol 88 (2) ◽  
pp. 298-305 ◽  
Author(s):  
Peter Laurberg
Keyword(s):  
Ionic Strength ◽  
Guinea Pig ◽  
Sucrose Gradient ◽  
Deae Cellulose ◽  
High Ionic Strength ◽  
Relative Distribution ◽  
Thyroid Extract ◽  
Reverse Triiodothyronine ◽  
Thyroid Secretion ◽  
Stable Iodine

ABSTRACT Thyroglobulin fractions rich and poor in new thyroglobulin were separated by means of DEAE-cellulose chromatography of dog thyroid extracts and by zonal ultracentrifugation in a sucrose gradient of guinea pig thyroid extract incubated at low temperature. The distribution of thyroxine, triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine in hydrolysates of the different fractions was estimated by radioimmunoassays. Following DEAE-cellulose chromatography there was a small but statistically significant increase in the T4/T3 ratio in thyroglobulin fractions eluted at high ionic strength - that is fractions relatively rich in stable iodine but poor in fresh thyroglobulin. There were no differences in the T4/rT3 ratios between the different fractions. The ratios between iodothyronines were almost identical in the various thyroglobulin fractions following zonal ultracentrifugation in a sucrose gradient of cold treated guinea pig thyroid extract. These findings lend no support to the possibility that a relatively high content of triiodothyronines in freshly synthesized thyroglobulin modulates the thyroid secretion towards a preferential secretion of triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine at the expense of the secretion of thyroxine.

scholarly journals Ferrierite and Its Delaminated Forms Modified with Copper as Effective Catalysts for NH3-SCO Process

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4885
Author(s):  
Aneta Święs ◽  
Małgorzata Rutkowska ◽  
Andrzej Kowalczyk ◽  
Urbano Díaz ◽  
Antonio E. Palomares ◽  
...  
Keyword(s):  
Copper Oxide ◽  
Ammonia Oxidation ◽  
Catalytic Reduction ◽  
Surface Acidity ◽  
Selective Reduction ◽  
Exchange Method ◽  
Copper Species ◽  
Selective Catalytic Oxidation ◽  
Catalytically Active ◽  
Copper Cations

Ferrierites and their delaminated forms (ITQ-6), containing aluminum or titanium in the zeolite framework, were synthetized and modified with copper by an ion-exchange method. The obtained samples were characterized with respect to their chemical composition (ICP-OES), structure (XRD, UV-Vis DRS), textural parameters (N2-sorption), surface acidity (NH3-TPD), form and reducibility of deposited copper species (UV-Vis DRS and H2-TPR). Ferrierites and delaminated ITQ-6 zeolites modified with copper were studied as catalysts for the selective catalytic oxidation of ammonia to dinitrogen (NH3-SCO). It was shown that aggregated copper oxide species, which were preferentially formed on Ti-zeolites, were catalytically active in direct low-temperature ammonia oxidation to NO, while copper introduced into Al-zeolites was present mainly in the form of monomeric copper cations catalytically active in selective reduction of NO by ammonia to dinitrogen. It was postulated that ammonia oxidation in the presence of the studied catalysts proceeds according to the internal-selective catalytic reduction mechanism (i-SCR) and therefore the suitable ratio between aggregated copper oxide species and monomeric copper cations is necessary to obtain active and selective catalysts for the NH3-SCO process. Cu/Al-ITQ-6 presented the best catalytic properties possibly due to the most optimal ratio of these copper species.

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