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A simple and portable colorimetric sensor for colorimetric detection of UO 2 in aqueous solution based on vinylphosphonic acid functionalized gold nanoparticles (VPA-AuNPs) has been developed. The VPA-AuNPs solution was prepared by sodium borohydride reduction in the presence of vinylphosphonic acid. The addition of UO 2+ in aqueous solution based on vinylphosphonic acid functionalized gold nanoparticles (VPA-AuNPs) has been developed. The VPA-AuNPs solution was prepared by sodium borohydride reduction in the presence of vinylphosphonic acid. The addition of UO 2 2+ would induce aggregation of VPA-AuNPs, resulting in the color change from wine-red to blue, and red-shift of the ultraviolet-visible (UV-vis) spectra. The UO 2 2+ assay based on VPA-AuNPs showed good selectivity and sensitivity, with a limit of detection to be approximately 2.0 μM by naked eyes and 1.07 μM by UV-vis (S/N = 3) respectively. Additionally, a smartphone with a free application named "PhotoMetrix" was employed to estimate the color intensities (red, green, blue value) of VPA-AuNPs in the presence of UO 2 2+ with different concentrations, and the concentration of UO 2 2+ samples could be conveniently exported by the calculated univariate calibration curves. This method shows good feasibility for on-site UO 2 2+ detection in an aqueous solution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A large family of bifunctional 1,2,3-triazole derivatives that contain both a polyethylene glycol (PEG) chain and another functional fragment (e.g., a polymer, dendron, alcohol, carboxylic acid, allyl, fluorescence dye, redox-robust metal complex, or a β-cyclodextrin unit) has been synthesized by facile "click" chemistry and mildly coordinated to nanogold particles, thus providing stable water-soluble gold nanoparticles (AuNPs) in the size range 3.0-11.2 nm with various properties and applications. In particular, the sensing properties of these AuNPs are illustrated through the detection of an analogue of a warfare agent (i.e., sulfur mustard) by means of a fluorescence "turn-on" assay, and the catalytic activity of the smallest triazole-AuNPs (core of 3.0 nm) is excellent for the reduction of 4-nitrophenol in water., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The aim of these studies was to synthesize, characterize and evaluate the efficacy of pegylated gold nanoparticles (AuNPs) that differed in their PEG molecular weight, using PEG 550 and PEG 2000. The synthesis of the gold nanoparticles was carried out by modified Brust method with a diameter of 4-15 nm. The targeting agent folic acid was introduced by the covalent linkage. Finally, the anti-cancer drug docetaxel was encapsulated by the AuNPs by non covalent adsorption. The nanoparticles were characterized by transmission electron microscopy and used for in vitro studies against a hormone-responsive prostate cancer cell line, LnCaP. The loaded nanoparticles reduced the cell viability in more than 50% at concentrations of 6 nM and above after 144 h of treatment. Moreover, observation of prostate cancer cells by optical microscopy showed damage to the cells after exposure to drug-loaded AuNPs while unloaded AuNPs had much less effect., (Copyright © 2013 Elsevier B.V. All rights reserved.)

"Click" chemistry now offers access to a great variety of triazoles, and the first example of a strategy to stabilize gold nanoparticles (AuNPs) with a new 1,2,3-triazole-mPEG ligand is developed here together with preliminary examples of possible applications.

A highly sensitive, selective, and quick colorimetric assay for CrIII detection has been developed by using iminodiacetate (IDA) modified gold nanoparticles (AuNPs). These AuNPs were prepared by a hydrothermal method with IDA as both a reductant and a stabilizer. The as-prepared IDA-AuNPs display good selectivity for colorimetric detection of CrIII in aqueous solution over 15 other metal ions. In the presence of an increasing amount of CrIII, the color of the IDA-AuNPs changes gradually from red to blue, together with a redshift of the plasmon absorption, within 1 min. The detection limit of CrIII was approximately 1.5 µM for the naked eye and 0.3 µM for UV/Vis spectroscopy. A good linear relationship was obtained between the logarithm of the ratios (A650/A520) and the concentration of CrIII over the range 0.3-3 µM. The feasibility of this technique was evaluated for the successful detection of CrIII in drinking-water samples, with good recoveries. [ABSTRACT FROM AUTHOR]

A large family of bifunctional 1,2,3-triazole derivatives that contain both a polyethylene glycol (PEG) chain and another functional fragment (e.g., a polymer, dendron, alcohol, carboxylic acid, allyl, fluorescence dye, redox-robust metal complex, or a β-cyclodextrin unit) has been synthesized by facile 'click' chemistry and mildly coordinated to nanogold particles, thus providing stable water-soluble gold nanoparticles (AuNPs) in the size range 3.0-11.2 nm with various properties and applications. In particular, the sensing properties of these AuNPs are illustrated through the detection of an analogue of a warfare agent (i.e., sulfur mustard) by means of a fluorescence 'turn-on' assay, and the catalytic activity of the smallest triazole-AuNPs (core of 3.0 nm) is excellent for the reduction of 4-nitrophenol in water. [ABSTRACT FROM AUTHOR]

Abstract: General principles and recent developments in the synthesis of gold nanoparticles (AuNPs) are reviewed. The “in situ” Turkevich-Frens and Brust-Schiffrin methods are still major synthetic routes, with citrate and thiolate ligands, respectively, that have been improved and extended to macromolecules including biomacromolecules with a large biomedical potential of optical and theranostic applications. Along this line, however, recently developed seed-growth methods have allowed a precise control of AuNP sizes in a broad range and multiple shapes. AuNPs and core@shell bimetallic MAuNPs loosely stabilized by nitrogen and oxygen atoms of embedding polymers and dendrimers and composite solid-state materials containing AuNPs with supports including oxides, carbons, mesoporous materials and molecular organic frameworks (MOFs) have attracted much interest because of their catalytic applications. [Copyright &y& Elsevier]

Review: 429 refs. [ABSTRACT FROM AUTHOR]

A highly sensitive, selective, and quick colorimetric assay for CrIII detection has been developed by using iminodiacetate (IDA) modified gold nanoparticles (AuNPs). These AuNPs were prepared by a hydrothermal method with IDA as both a reductant and a stabilizer. The as-prepared IDA-AuNPs display good selectivity for colorimetric detection of CrIII in aqueous solution over 15 other metal ions. In the presence of an increasing amount of CrIII, the color of the IDA-AuNPs changes gradually from red to blue, together with a redshift of the plasmon absorption, within 1 min. The detection limit of CrIII was approximately 1.5 µM for the naked eye and 0.3 µM for UV/Vis spectroscopy. A good linear relationship was obtained between the logarithm of the ratios (A650/A520) and the concentration of CrIII over the range 0.3-3 µM. The feasibility of this technique was evaluated for the successful detection of CrIII in drinking-water samples, with good recoveries. [ABSTRACT FROM AUTHOR]