scholarly journals Size-controlled and water-soluble gold nanoparticles using UV-induced ligand exchange and phase transfer

2018 ◽  
Vol 54 (95) ◽  
pp. 13355-13358 ◽  
Author(s):  
Jan Bart ten Hove ◽  
Laura M. I. Schijven ◽  
Junyou Wang ◽  
Aldrik H. Velders
Keyword(s):  
Gold Nanoparticles ◽  
Ligand Exchange ◽  
Water Solubility ◽  
Phase Transfer ◽  
Water Soluble ◽  
Size Distributions ◽  
Seeded Growth ◽  
Growth Approach ◽  
Size Controlled

Oleylamine-capped gold nanoparticles (AuNPs) with sizes ranging from 5 to 13 nm and narrow size distributions (<10%) are synthesized by using a seeded growth approach. Water-solubility is achieved by using a UV-induced ligand exchange approach.

Water-Soluble N-Heterocyclic Carbene-Protected Gold Nanoparticles: Size-Controlled Synthesis, Stability, and Optical Properties

2017 ◽  
Vol 129 (22) ◽  
pp. 6294-6298 ◽  
Author(s):  
Kirsi Salorinne ◽  
Renee W. Y. Man ◽  
Chien-Hung Li ◽  
Masayasu Taki ◽  
Masakazu Nambo ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Optical Properties ◽  
Water Soluble ◽  
Controlled Synthesis ◽  
Size Controlled

Size-controlled preparation of gold nanoparticles with novel pH responsive gemini amphiphiles

2015 ◽  
Vol 3 (24) ◽  
pp. 6334-6340 ◽  
Author(s):  
Li Cheng ◽  
Xuefeng Li ◽  
Jinfeng Dong
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Phase Transfer ◽  
Ph Sensitive ◽  
Ph Responsive ◽  
Gemini Amphiphiles ◽  
Controlled Preparation ◽  
Size Controlled

Novel pH sensitive Di-CnPh gemini amphiphiles can act as both the phase-transfer reagent and stabilizer to make extremely small Au nanoparticles.

Easy and Fast Phase Transfer of CTAB Stabilised Gold Nanoparticles from Water to Organic Phase

2015 ◽  
Vol 229 (1-2) ◽  
Author(s):  
Susann Kittler ◽  
Stephen G. Hickey ◽  
Thomas Wolff ◽  
Alexander Eychmüller
Keyword(s):  
Gold Nanoparticles ◽  
Ligand Exchange ◽  
Phase Transfer ◽  
Ammonium Bromide ◽  
Fast Phase ◽  
Before And After ◽  
Cheap Method ◽  
Different Shapes ◽  
Hexadecyltrimethyl Ammonium Bromide ◽  
Anisotropic Gold Nanoparticles

AbstractSpheric and anisotropic gold nanoparticles (GNPs) such as rods, stars or nanoprism prepared using hexadecyltrimethyl ammonium bromide (CTAB) as the stabilising agent have received a great deal of interest in the last years. The literature procedures exploited lead to GNPs in aqueous solution. We herein describe a fast, efficient, and cheap method to transfer particles of different shapes from water into toluene solution via ligand exchange (CTAB to dodecanethiol), which was mediated by acetone as a cosolvent. Absorption spectra and TEM-pictures before and after the transfer revealed that the particles survived the transfer intact and without change in shape.

Toward Smaller Aqueous-Phase Plasmonic Gold Nanoparticles: High-Stability Thiolate-Protected ~ 4.5 Nm Cores

2019 ◽  
Author(s):  
M. Mozammel Hoque ◽  
Kathryn M. Mayer ◽  
Arturo Ponce ◽  
Marcos M. Alvarez ◽  
Robert L. Whetten
Keyword(s):  
Gold Nanoparticles ◽  
Ligand Exchange ◽  
Shape Control ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Localized Surface Plasmon ◽  
Core Diameter ◽  
Gold Core ◽  
Ligand Shell ◽  
Vis Spectroscopy

<p>Most applications of aqueous plasmonic gold nanoparticles benefit from control of the core size and shape, control of the nature of the ligand shell, and a simple and widely applicable preparation method. Surface functionalization of such nanoparticles is readily achievable but is restricted to water-soluble ligands. Here we have obtained highly monodisperse and stable <i>smaller </i>aqueous gold nanoparticles (core diameter ~ 4.5-nm), prepared from citrate-tannate precursors via ligand exchange with each of three distinct thiolates: 11-mercaptoundecanoic acid, a-R-lipoic acid, and para-mercaptobenzoic acid. These are characterized by UV-Vis spectroscopy for plasmonic properties; FTIR spectroscopy for ligand exchange confirmation; X-ray diffractometry for structural analysis; and high-resolution transmission electron microscopy for structure and size determination. Chemical reduction induces a blueshift, maximally +0.02-eV, in the localized surface-plasmon resonances band; this is interpreted as an electronic (-) charging of the MPC gold core, corresponding to a -0.5-V change in electrochemical potential.</p>

Water-Soluble N-Heterocyclic Carbene-Protected Gold Nanoparticles: Size-Controlled Synthesis, Stability, and Optical Properties

2017 ◽  
Vol 56 (22) ◽  
pp. 6198-6202 ◽  
Author(s):  
Kirsi Salorinne ◽  
Renee W. Y. Man ◽  
Chien-Hung Li ◽  
Masayasu Taki ◽  
Masakazu Nambo ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Optical Properties ◽  
Water Soluble ◽  
Controlled Synthesis ◽  
Size Controlled

scholarly journals Toward Smaller Aqueous-Phase Plasmonic Gold Nanoparticles: High-Stability Thiolate-Protected ~ 4.5 Nm Cores

2019 ◽  
Author(s):  
M. Mozammel Hoque ◽  
Kathryn M. Mayer ◽  
Arturo Ponce ◽  
Marcos M. Alvarez ◽  
Robert L. Whetten
Keyword(s):  
Gold Nanoparticles ◽  
Ligand Exchange ◽  
Shape Control ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Localized Surface Plasmon ◽  
Core Diameter ◽  
Gold Core ◽  
Ligand Shell ◽  
Vis Spectroscopy

<p>Most applications of aqueous plasmonic gold nanoparticles benefit from control of the core size and shape, control of the nature of the ligand shell, and a simple and widely applicable preparation method. Surface functionalization of such nanoparticles is readily achievable but is restricted to water-soluble ligands. Here we have obtained highly monodisperse and stable <i>smaller </i>aqueous gold nanoparticles (core diameter ~ 4.5-nm), prepared from citrate-tannate precursors via ligand exchange with each of three distinct thiolates: 11-mercaptoundecanoic acid, a-R-lipoic acid, and para-mercaptobenzoic acid. These are characterized by UV-Vis spectroscopy for plasmonic properties; FTIR spectroscopy for ligand exchange confirmation; X-ray diffractometry for structural analysis; and high-resolution transmission electron microscopy for structure and size determination. Chemical reduction induces a blueshift, maximally +0.02-eV, in the localized surface-plasmon resonances band; this is interpreted as an electronic (-) charging of the MPC gold core, corresponding to a -0.5-V change in electrochemical potential.</p>

BODIPY Fluorophores for Membrane Potential Imaging

2019 ◽  
Author(s):  
Jenna Franke ◽  
Benjamin Raliski ◽  
Steven Boggess ◽  
Divya Natesan ◽  
Evan Koretsky ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Water Solubility ◽  
Water Soluble ◽  
Voltage Sensitivity ◽  
Chemical Transformations ◽  
Direct Modification ◽  
Biological Compatibility ◽  
Meso Position ◽  
Ionizable Groups ◽  
Boron Center

Fluorophores based on the BODIPY scaffold are prized for their tunable excitation and emission profiles, mild syntheses, and biological compatibility. Improving the water-solubility of BODIPY dyes remains an outstanding challenge. The development of water-soluble BODIPY dyes usually involves direct modification of the BODIPY fluorophore core with ionizable groups or substitution at the boron center. While these strategies are effective for the generation of water-soluble fluorophores, they are challenging to implement when developing BODIPY-based indicators: direct modification of BODIPY core can disrupt the electronics of the dye, complicating the design of functional indicators; and substitution at the boron center often renders the resultant BODIPY incompatible with the chemical transformations required to generate fluorescent sensors. In this study, we show that BODIPYs bearing a sulfonated aromatic group at the meso position provide a general solution for water-soluble BODIPYs. We outline the route to a suite of 5 new sulfonated BODIPYs with 2,6-disubstitution patterns spanning a range of electron-donating and -withdrawing propensities. To highlight the utility of these new, sulfonated BODIPYs, we further functionalize them to access 13 new, BODIPY-based voltage-sensitive fluorophores. The most sensitive of these BODIPY VF dyes displays a 48% ΔF/F per 100 mV in mammalian cells. Two additional BODIPY VFs show good voltage sensitivity (≥24% ΔF/F) and excellent brightness in cells. These compounds can report on action potential dynamics in both mammalian neurons and human stem cell-derived cardiomyocytes. Accessing a range of substituents in the context of a water soluble BODIPY fluorophore provides opportunities to tune the electronic properties of water-soluble BODIPY dyes for functional indicators.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

scholarly journals Synthesis, Characterization and Bactericidal Activity of a 4-Ammoniumbuthylstyrene-Based Random Copolymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Silvana Alfei ◽  
Gabriella Piatti ◽  
Debora Caviglia ◽  
Anna Maria Schito
Keyword(s):  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
Random Copolymer ◽  
Water Soluble ◽  
Cationic Polymers ◽  
Severe Infections

The growing resistance of bacteria to current chemotherapy is a global concern that urgently requires new and effective antimicrobial agents, aimed at curing untreatable infection, reducing unacceptable healthcare costs and human mortality. Cationic polymers, that mimic antimicrobial cationic peptides, represent promising broad-spectrum agents, being less susceptible to develop resistance than low molecular weight antibiotics. We, thus, designed, and herein report, the synthesis and physicochemical characterization of a water-soluble cationic copolymer (P5), obtained by copolymerizing the laboratory-made monomer 4-ammoniumbuthylstyrene hydrochloride with di-methyl-acrylamide as uncharged diluent. The antibacterial activity of P5 was assessed against several multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species. Except for strains characterized by modifications of the membrane charge, most of the tested isolates were sensible to the new molecule. P5 showed remarkable antibacterial activity against several isolates of genera Enterococcus, Staphylococcus, Pseudomonas, Klebsiella, and against Escherichia coli, Acinetobacter baumannii and Stenotrophomonas maltophilia, displaying a minimum MIC value of 3.15 µM. In time-killing and turbidimetric studies, P5 displayed a rapid non-lytic bactericidal activity. Due to its water-solubility and wide bactericidal spectrum, P5 could represent a promising novel agent capable of overcoming severe infections sustained by bacteria resistant the presently available antibiotics.

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