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>

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>

Localized Surface Plasmon Resonance Effect of Gold Nanoparticles Using 3-Mercaptopropionic Acid as Capping Material for Sensing Probe

2021 ◽  
Vol 891 ◽  
pp. 43-48
Author(s):  
Muhammad Tegar Pambudi ◽  
Suhandoko Dwi Isro ◽  
Priastuti Wulandari
Keyword(s):  
Gold Nanoparticles ◽  
Surface Plasmon Resonance ◽  
Ligand Exchange ◽  
Localized Surface Plasmon Resonance ◽  
Reduction Method ◽  
Colloidal Solution ◽  
Localized Surface Plasmon ◽  
Exchange Method ◽  
Vibrational Peak ◽  
Absorbance Spectra

Gold nanoparticles (AuNP) has been used in a wide range of applications especially in medicine and optoelectronic applications due to its localized surface plasmon resonance (LSPR) effect. LSPR observation of AuNP solution shows that the plasmonic peak in the absorbance spectra lies in the range of visible light around 520 nm with deep red-wine color. The optical characteristic is controlled by the size and shape of the nanoparticles including its surface functionalization. Our research is focused on the adsorption study of 3-mercaptopropionate (3-MP) on AuNP (AuMP) surface synthesized by ligand exchange method and also by direct reduction method. The characterizations are conducted by use of UV-vis and FTIR spectroscopies in order to investigate the effect of LSPR. The absorbance spectra show that both experimental methods of AuMP give a similar profile of red-shifted in the plasmonic peaks in comparison to that of citrate-capped AuNP as a reference from 519 nm to 520 nm. The ligand exchange method of AuMP synthesis results in an unstable colloidal solution after being stored for a week at room temperature while the reduction method results in a stable colloidal solution of AuMP even though it has been stored for 2 months. The FTIR spectra show the difference in vibrational peak intensities between the 3-MP on AuNP and the 3-MPA as reference. The peak of carboxylate (COO-) asymmetric stretching is shifted to low frequency from 1708 cm-1 to 1632 cm-1 indicate the effect of LSPR while the shift to high frequencies for some vibrational peak intensities relates to the strong effect of chemical coordination between gold and capping material. The simulation of the vibration energy by use of the Density Functional Theory (DFT) method shows a similar tendency to that of the peak intensities along the infrared spectrum from experimental results.

Facile synthesis of water-soluble graphene-based composite: Non-covalently functionalized with chitosan-ionic liquid conjugation

2016 ◽  
Vol 09 (03) ◽  
pp. 1650045 ◽  
Author(s):  
Pei-Ying Li ◽  
Kai-Yu Cheng ◽  
Xiu-Cheng Zheng ◽  
Pu Liu ◽  
Xiu-Juan Xu
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Chemical Reduction ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Text Interaction

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.

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.

Evolution of the Ligand Shell Morphology during Ligand Exchange Reactions on Gold Nanoparticles

2017 ◽  
Vol 56 (43) ◽  
pp. 13521-13525 ◽  
Author(s):  
Zhi Luo ◽  
Jing Hou ◽  
Laure Menin ◽  
Quy Khac Ong ◽  
Francesco Stellacci
Keyword(s):  
Gold Nanoparticles ◽  
Ligand Exchange ◽  
Shell Morphology ◽  
Exchange Reactions ◽  
Ligand Shell

scholarly journals Optical Properties of Linoleic Acid Protected Gold Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Ratan Das ◽  
Siddartha S. Nath ◽  
Ramendu Bhattacharjee
Keyword(s):  
Gold Nanoparticles ◽  
Linoleic Acid ◽  
Fluorescence Spectra ◽  
Au Nanoparticles ◽  
Chemical Reduction ◽  
Colloidal Dispersion ◽  
Visible Range ◽  
Absorption Bands ◽  
Transmission Electron ◽  
Vis Spectroscopy

Linoleic acid-protected gold nanoparticles have been synthesized through the chemical reduction of tetrachloroaurate ions by ethanol in presence of sodium linoleate. The structure of these nanoparticles is investigated using transmission electron microscopy, which shows that the Au nanoparticles are spherical in shape with a narrow size distribution which ranges from 8 to 15 nm. Colloidal dispersion of gold nanoparticles in cyclohexane exhibits absorption bands in the ultraviolet-visible range due to surface plasmon resonance, with absorption maximum at 530 nm. Fluorescence spectra of gold nanoparticles also show an emission peak at 610 nm when illuminated at 450 nm. UV-Vis spectroscopy reveals that these nanoparticles remain stable for 10 days.

scholarly journals The Effect of Surface Functionalization on the Immobilization of Gold Nanoparticles on Graphene Sheets

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Min Song ◽  
Juan Xu ◽  
Changzi Wu
Keyword(s):  
Gold Nanoparticles ◽  
Surface Functionalization ◽  
Chemical Reduction ◽  
Synthesis Process ◽  
Functionalized Graphene ◽  
Graphene Surface ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Gold Composites ◽  
Effect Of Surface

In our study, graphene oxide is synthesized by Hummers method. And then, carboxylic acid functionalized graphene (graphene-COOH), thiol-functionalized graphene (graphene-SH), and highly dispersive graphene are prepared by chemical modification of respective groups on the graphene surface. Furthermore, we explore a solution-based approach to prepare three differently functionalized graphene-gold composites by one-step chemical reduction ofAuCl4 -ions in respective functionalized graphene suspensions, where the gold nanoparticles are deposited on the functionalized graphene surface during their synthesis process. In addition, we compare the influence of surface functionalization on the growth of gold nanoparticles on graphene surface. Transmission electron morphology (TEM) and ultraviolet-visible (UV-Vis) spectroscopy are employed to study the effect of surface functionalities on AuNPs distribution onto the graphene surface and demonstrate the successful immobilization of AuNPs on graphene surface.

Evolution of the Ligand Shell Morphology during Ligand Exchange Reactions on Gold Nanoparticles

2017 ◽  
Vol 129 (43) ◽  
pp. 13706-13710 ◽  
Author(s):  
Zhi Luo ◽  
Jing Hou ◽  
Laure Menin ◽  
Quy Khac Ong ◽  
Francesco Stellacci
Keyword(s):  
Gold Nanoparticles ◽  
Ligand Exchange ◽  
Shell Morphology ◽  
Exchange Reactions ◽  
Ligand Shell

scholarly journals Poly (Vinyl Alcohol) Assisted Synthesis and Anti-Solvent Precipitation of Gold Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2359
Author(s):  
Zhen Liu ◽  
Olivia L. Lanier ◽  
Anuj Chauhan
Keyword(s):  
Gold Nanoparticles ◽  
Size Distribution ◽  
Vinyl Alcohol ◽  
Trisodium Citrate ◽  
Precipitation Method ◽  
Localized Surface Plasmon ◽  
Poly Vinyl Alcohol ◽  
Synthesis Parameters ◽  
Vis Spectroscopy ◽  
Nanoparticle Morphology

Gold nanoparticles (GNPs) are commonly synthesized using the Turkevich method, but there are limitations on the maximum concentration of gold nanoparticles that can be achieved using this method (often < 1 mM (=0.34 mg/mL) gold precursor loading). Here, we report an inverse Turkevich method which significantly increases the concentration of gold nanoparticles (up to 5-fold) in the aqueous phase by introducing poly (vinyl alcohol) (PVA) to the synthesis system for stabilization. The aim of this study is to understand the effect of PVA and other synthesis parameters, such as trisodium citrate and tetrachloroauric acid concentration, with the goal of maximizing concentration while maintaining gold nanoparticle morphology, stability, and narrow size distribution. The size distribution of GNPs is investigated for a range of parameters by dynamic light scattering and electron microscopy, and ultraviolet-visible (UV–vis) spectroscopy is also utilized to explore the localized surface plasmon resonance (LSPR). Further, the interaction between GNPs and PVA is investigated by Fourier-transform infrared spectroscopy. In addition to increasing the gold loading by varying synthesis parameters, we also develop a novel anti-solvent precipitation method for the PVA-coated GNPs, which enables continuous condensation and purification of GNPs by forming a gold/PVA nanocomposite.

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