Particle Size Evolution during the Synthesis of Gold Nanoparticles Using In Situ Time-Resolved UV–Vis Spectroscopy: An Experimental and Theoretical Study Unravelling the Effect of Adsorbed Gold Precursor Species

Abstract The composite of green synthesized gold nanoparticles (Au NPs)-doped hydroxyapatite (HA) has been prepared. The gold nanoparticles were produced via bioreduction of HAuCl4 with Clitoria ternatea flower extract, and utilized in the synthesis of hydroxyapatite using Ca(OH)2 and ammonium diphosphate as precursor. The aim of this research is to study the structural analysis of the composite and antibacterial activity test toward Eschericia coli, Staphylococcus aureus, Klebsiela pneumoniae, and Streptococcus pyogenes. In addition, the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The monitoring of gold nanoparticles formation was conducted by UV–vis spectroscopy and particle size analyses, meanwhile the synthesized composite was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that homogeneously dispersed gold nanoparticles in HA structure was obtained with the particle size ranging at 5-80 nm. The nanocomposite demonstrated antibacterial activity against tested bacteria. The nanocomposite expressed an antioxidant activity as shown by the DPPH scavenging activity of 66 and 58% at the concentration of 100 μg/mL and 50 μg/mL, respectively.

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Tandem X-ray absorption spectroscopy and scattering for in situ time-resolved monitoring of gold nanoparticle mechanosynthesis

Chemical Communications ◽

10.1039/d0cc03862h ◽

2020 ◽

Vol 56 (71) ◽

pp. 10329-10332 ◽

Cited By ~ 1

Author(s):

Paulo F. M. de Oliveira ◽

Adam A. L. Michalchuk ◽

Ana Guilherme Buzanich ◽

Ralf Bienert ◽

Roberto M. Torresi ◽

...

Keyword(s):

Gold Nanoparticles ◽

Gold Nanoparticle ◽

Absorption Spectroscopy ◽

Mechanochemical Synthesis ◽

Time Resolved ◽

X Ray ◽

X Ray Absorption

A new tandem approach combines XRD and XANES for time-resolved in situ monitoring of the mechanochemical synthesis of gold nanoparticles.

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In Situ Time-Resolved Decomposition of β-Hydride Phase in Palladium Nanoparticles Coated with Metal-Organic Framework

Metals ◽

10.3390/met10060810 ◽

2020 ◽

Vol 10 (6) ◽

pp. 810

Author(s):

Mikhail V. Kirichkov ◽

Aram L. Bugaev ◽

Alina A. Skorynina ◽

Vera V. Butova ◽

Andriy P. Budnyk ◽

...

Keyword(s):

Phase Transition ◽

Particle Size ◽

Hydrogen Adsorption ◽

Metal Organic Framework ◽

Pd Nanoparticles ◽

Time Resolved ◽

Metal Organic ◽

Hydride Phases ◽

Organic Framework

The formation of palladium hydrides is a well-known phenomenon, observed for both bulk and nanosized samples. The kinetics of hydrogen adsorption/desorption strongly depends on the particle size and shape, as well as the type of support and/or coating of the particles. In addition, the structural properties of hydride phases and their distribution also depend on the particle size. In this work, we report on the in situ characterization of palladium nanocubes coated with HKUST-1 metal-organic framework (Pd@HKUST-1) during desorption of hydrogen by means of synchrotron-based time-resolved X-ray powder diffraction. A slower hydrogen desorption, compared to smaller sized Pd nanoparticles was observed. Rietveld refinement of the time-resolved data revealed the remarkable stability of the lattice parameters of α- and β-hydride phases of palladium during the α- to β- phase transition, denoting the behavior more similar to the bulk materials than nanoparticles. The stability in the crystal sizes for both α- and β-hydride phases during the phase transition indicates that no sub-domains are formed within a single particle during the phase transition.

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Salt-induced cluster formation of gold nanoparticles followed by stopped-flow SAXS, DLS and extinction spectroscopy

Physical Chemistry Chemical Physics ◽

10.1039/c7cp01807j ◽

2017 ◽

Vol 19 (25) ◽

pp. 16348-16357 ◽

Cited By ~ 8

Author(s):

Nico Carl ◽

Sylvain Prévost ◽

Joseph P. S. Fitzgerald ◽

Matthias Karg

Keyword(s):

Gold Nanoparticles ◽

Cluster Formation ◽

Stopped Flow ◽

Time Resolved

The salt-induced cluster formation of negatively charged gold nanoparticles was studied by time-resolved DLS, stopped-flow SAXS and in-situ extinction spectroscopy.

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Reverse Coarsening and the Control of Particle Size Distribution through Surfactant

Applied Sciences ◽

10.3390/app10155359 ◽

2020 ◽

Vol 10 (15) ◽

pp. 5359

Author(s):

Victor M. Burlakov ◽

Alain Goriely

Keyword(s):

Particle Size ◽

Surface Energy ◽

Particle Size Distribution ◽

Size Distribution ◽

Surface Area ◽

Particle Nucleation ◽

Size Evolution ◽

Energy Renormalization ◽

In Situ Replacement

The minimization of surface area, as a result of the minimization of (positive) surface energy, is a well-known driving force behind the spontaneous broadening of (nano) particle size distribution. We show that surfactant molecules binding to particle surfaces effectively decrease the surface energy and may change its sign. In this case, contrary to the expected broadening behavior, a minimum of free energy is achieved at the maximum surface area for all particles, i.e., when the particles are identical. Numerical simulations based on the classical Lifshitz–Slyozov–Wagner theory with surfactant-induced surface energy renormalization confirm the collapse of the particle size distribution. As the particle size evolution is much slower than particle nucleation and growth, the manipulation of surface energy with in-situ replacement of surfactant molecules provides a method for controlling particle size distribution with great potential for creating mono-disperse nanoparticles, a key goal of nanotechnology.

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Synthesis and analytical characterization of gold nanoparticles for anticancer drug delivery application

10.7287/peerj.preprints.1832v1 ◽

2016 ◽

Author(s):

Elżbieta U. Stolarczyk ◽

Krzysztof Stolarczyk ◽

Marek Kubiszewski ◽

Marta Łaszcz ◽

Wioleta Maruszak

Keyword(s):

Particle Size ◽

Gold Nanoparticles ◽

Raman Spectroscopy ◽

Capillary Electrophoresis ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Electrochemical Techniques ◽

Vis Spectroscopy

For many years research has been carried out to form selective drug carriers. Gold nanoparticles (AuNP) are of particular interest. New perspectives of these nanoparticles as drug carries include: the use of drugs which are poorly soluble in water, targeted delivery of drugs, transport by barrier membranes, the possibility of macromolecular drug release, "combined" treatment - two or more drugs, securing faster mechanisms of action and improved efficiency of drugs. Drug-modified gold nanoparticles (R-AuNP) have been synthesized in a single-phase system based on the reduction of hydrogen tetrachloroaurate (III) using the stabilizing ligand. The color change from yellow to deep ruby red indicated the formation of gold nanoparticles. The formation of stabilized gold nanoparticles was confirmed by the observation of the surface plasmon resonance band. Varying drug concentrations and kinds of solvents were used for the reduction of tetrachloroaurate to determine the effect of drug/ligand concentration and solvent type on the formation of AuNPs. The stability of newly synthesized R-AuNPs was characterized using UV-Vis spectroscopy. The conjugated particles (the resulting AuNPs) were characterized by several techniques, including transmission electron microscopy (TEM), UV-Vis spectroscopy, infrared spectroscopy (IR), Raman spectroscopy, nuclear magnetic resonance spectroscopy (NMR), capillary electrophoresis, electrochemical techniques and zeta potential measurement. In any application of the AuNPs, it is important first to determine their basic physico-chemical characteristics, such as, e.g. size, shape, mono- or polydispersity, UV–Vis spectra, electrokinetic potential as well as other special parameters and analytical methods employed in the characterization of the AuNPs. TEM is a powerful and straightforward method for the determination of size (including size distribution) and shape of the AuNPs. UV–Vis absorption spectrophotometry allows for an in situ direct analysis of colloidal solutions. The position of the observed band maxima (typically in the range 500 – 600 nm) is usually related to particle size. However, the position of the surface-plasmon resonance (SPR) maximum cannot be directly related to the particle size of the NPs and other factors have to be considered. The capillary electrophoresis is the method applied to confirm the formation of nanoparticles as well as to determine the drug residuals in the leachate during the purification of the conjugates. By means of infrared and Raman spectroscopy it is possible to study the molecular species deposited on the AuNPs. The NMR spectroscopy and electrochemical techniques are used to confirm the attached drugs. Complete structural characterization of the organic molecules attached to the AuNPs surface was carried out.

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Catalytic Degradation of Methylene Blue Using Gold Nanoparticles Capped by Polyoxyethylene Cholesteryl Ether

Advanced Science Engineering and Medicine ◽

10.1166/asem.2020.2679 ◽

2020 ◽

Vol 12 (10) ◽

pp. 1236-1240

Author(s):

Gajendra Rajput ◽

Niki Pandya

Keyword(s):

Gold Nanoparticles ◽

Synthesis Method ◽

Surfactant Solution ◽

Complete Characterization ◽

Positive Development ◽

Previous Part ◽

Vis Spectroscopy ◽

Future Direction

Simple spontaneous and eco-friendly green synthesis method for ultra-stable and catalytic gold nanoparticles (AuNPs) were synthesized through Polyoxyethylene cholesteryl ether (ChEO10) and sodium tetrachloroaurate (III) dihydrate (Na [AuCl4]-2H2O) were prepared at 27 °C (AuNPs were formed in < 2 h). Here the creation of distinct AuNPs is supported by reductive ChEO10 surfactant solution via complexation and in-situ reduction of AuCl4− ions in which ChEO10 acts as self-reducing and stabilising agent. This method is considered as simple and green. The positive development of colloidal AuNPs was monitored by simple UV-Vis spectroscopy. The complete characterization of synthesizing AuNPs was done in the previous part. The resulting AuNPs reveal outstanding catalytic properties for degradation of Methyl Blue (MB) to Leucomethylene blue (LMB) in the presence of NaBH4. We further comment on challenges and future direction of this exciting and rapidly expanding area of research.

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The Influence of the Peptide Molar Ratios on the Functionalization of Gold Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.872.94 ◽

2013 ◽

Vol 872 ◽

pp. 94-105

Author(s):

Mayra C. Ramirez-Camacho ◽

Inga Tuzovskaya ◽

Nina Bogdanchikova ◽

Alexey Pestryakov ◽

Arturo Susarrey-Arce ◽

...

Keyword(s):

Particle Size ◽

Gold Nanoparticles ◽

Particle Size Distribution ◽

Size Distribution ◽

Sodium Citrate ◽

Red Shift ◽

Molar Ratio ◽

Narrow Particle Size Distribution ◽

Plasmon Peak ◽

Vis Spectroscopy

Au nanoparticles (NPs) functionalized with L-cysteine (Cys) and cysteine-glycine (Cys-Gly) were synthetized. The AuNPs were prepared using sodium citrate as reducing agent. The influence of the molar concentrations of Cys and Cys-Gly, as well as the sodium citrate is studied on particle size and particle size distribution. TEM measurements revealed the formation of AuNPs with diameter in the range 5-35 nm which corresponds to nontoxic sizes [we should add a reference here, perhaps number one]. The optimal particle size for biomedical application along with narrow particle size distribution was observed for samples prepared with molar ratio of CAu:Ccitrate = 1:10. The results of UV-Vis spectroscopy revealed the interaction of the AuNPs with Cys and Gly-Cys demonstrated by a visible change in the absorption intensities of the plasmon peak located at 520 nm after AuNP functionalization and a slight shifting of this gold nanoparticles plasmon peak. Thus, any dielectric shell on surface of particles with more refraction index (and, correspondingly, dielectric function) can produce the particles with the red shift. Such effect of the surface shell with red-shift in the range of few nanometers observed for the AuNPs functionalized with Cys and Cys-Gly (Fig. 4) can be interpreted as thin or discontinuous layer of aminoacid molecules according to the data of optical spectra simulation.

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