Hybrid Microgels Containing Gold Nanoparticles

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Andrij Pich ◽  
Arpita Karak ◽  
Yan Lu ◽  
Anup K. Ghosh ◽  
Hans-Juergen P. Adler
Keyword(s):  
Gold Nanoparticles ◽  
Sodium Citrate ◽  
Colloidal Stability ◽  
Nano Particles ◽  
Composite Particles ◽  
Temperature Sensitive ◽  
Chloroauric Acid ◽  
Gold Nano Particles ◽  
Hybrid Microgels

AbstractIn present paper we report on a preparation of hybrid microgels filled with gold nano-particles (AuNPs). Temperature-sensitive VCL/AAEM microgels have been used as containers for deposition of Au by in situ formation of gold nano-particles. Synthesis of AuNPs has been performed by two methods: a) reduction of chloroauric acid with sodium borhydride and b) reduction of chloroauric acid by sodium citrate under ultrasonic agitation. In both cases AuNPs were deposited directly into microgels leading to formation of composite particles which exhibit temperature-sensitive properties, tunable gold contents and high colloidal stability. The influence of Au load on microgel size, morphology, swellingdeswelling behaviour and stability is discussed.

Seed-mediated synthesis and PEG coating of gold nanoparticles for controlling morphology and sizes

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3353-3360
Author(s):  
Susana Helena Arellano Ramírez ◽  
Perla García Casillas ◽  
Christian Chapa González
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Infrared Spectrometry ◽  
Ammonium Bromide ◽  
Chloroauric Acid ◽  
Vis Spectroscopy ◽  
Seed Mediated ◽  
Peg Coating

AbstractA significant area of research is biomedical applications of nanoparticles which involves efforts to control the physicochemical properties through simple and scalable processes. Gold nanoparticles have received considerable attention due to their unique properties that they exhibit based on their morphology. Gold nanospheres (AuNSs) and nanorods (AuNRs) were prepared with a seed-mediated method followed of polyethylene glycol (PEG)-coating. The seeds were prepared with 0.1 M cetyltrimethyl-ammonium bromide (CTAB), 0.005 M chloroauric acid (HAuCl4), and 0.01 M sodium borohydride (NaBH4) solution. Gold nanoparticles with spherical morphology was achieved by growth by aggregation at room temperature, while to achieve the rod morphology 0.1 M silver nitrate (AgNO3) and 0.1 M ascorbic acid solution were added. The gold nanoparticles obtained by the seed-mediated synthesis have spherical or rod shapes, depending on the experimental conditions, and a uniform particle size. Surface functionalization was developed using polyethylene glycol. Morphology, and size distribution of AuNPs were evaluated by Field Emission Scanning Electron Microscopy. The average size of AuNSs, and AuNRs was 7.85nm and 7.96 x 31.47nm respectively. Fourier transform infrared spectrometry was performed to corroborate the presence of PEG in the AuNPs surface. Additionally, suspensions of AuNSs and AuNRs were evaluated by UV-Vis spectroscopy. Gold nanoparticles were stored for several days at room temperature and it was observed that the colloidal stability increased once gold nanoparticles were coated with PEG due to the shield formed in the surface of the NPs and the increase in size which were 9.65±1.90 nm of diameter for AuNSs and for AuNRs were 29.03±5.88 and 8.39±1.02 nm for length and transverse axis, respectively.

Optimization of Gold Nanoparticles Synthesis using Design of Experiments Technique

2017 ◽  
Vol 68 (7) ◽  
pp. 1518-1423
Author(s):  
Adina Turcu Stiolica ◽  
Mariana Popescu ◽  
Maria Viorica Bubulica ◽  
Carmen Nicoleta Oancea ◽  
Claudiu Nicolicescu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Design Of Experiments ◽  
Process Model ◽  
Sodium Citrate ◽  
Drug Carriers ◽  
Chloroauric Acid ◽  
Gold Colloids ◽  
Citrate Concentration ◽  
Vis Spectroscopy

Gold nanoparticles are considered the newest drug carriers for different diseases. Therefore it is appropriate continuous optimization of their preparation. In this study, gold colloids with an average size of 1 - 26 nm were obtained by the reduction of tetrachloroauric acid with trisodium citrate. The nanomaterials were characterized by UV-Vis spectroscopy and dynamic light scattering technique. In addition, zeta potential was measured for samples synthesized in order to determine the stability of the colloids. A Two-level Full Factorial design was chosen to determine the optimum set of process parameters (chloroauric acid concentration and sodium citrate concentration) and their effect on various gold nanoparticles characteristics (size and zeta potential). These effects were quantified using Design of Experiments (DoE) with 5 runs and 1 centerpoint. The selected objective and process model in this investigation are screening and interaction. Findings from this research show that to obtain particles larger than 35 nm, it is recommended to increase sodium citrate concentration, at low chloroauric acid values. These conditions will help to achieve smaller zeta potential, too.

In situ synthesis of multidentate PEGylated chitosan modified gold nanoparticles with good stability and biocompatibility

RSC Advances ◽  
2015 ◽  
Vol 5 (86) ◽  
pp. 70109-70116 ◽  
Author(s):  
Gongyan Liu ◽  
Quanqing Luo ◽  
Haibo Wang ◽  
Weihua Zhuang ◽  
Yunbing Wang
Keyword(s):  
Gold Nanoparticles ◽  
Surface Coating ◽  
Colloidal Stability ◽  
Biological Systems ◽  
In Situ Synthesis ◽  
Good Stability

To realize desirable functions in the rather complex biological systems, a suitable surface coating is desirable for gold nanoparticles, which plays an important role in their colloidal stability and biocompatibility.

scholarly journals Intratumoral generation of photothermal gold nanoparticles through a vectorized biomineralization of ionic gold

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Aaron S. Schwartz-Duval ◽  
Christian J. Konopka ◽  
Parikshit Moitra ◽  
Enrique A. Daza ◽  
Indrajit Srivastava ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Incubation Time ◽  
Biomedical Applications ◽  
Gold Clusters ◽  
Chloroauric Acid ◽  
Delivery Vector ◽  
Biomedical Potential ◽  
Ionic Gold

Abstract Various cancer cells have been demonstrated to have the capacity to form plasmonic gold nanoparticles when chloroauric acid is introduced to their cellular microenvironment. But their biomedical applications are limited, particularly considering the millimolar concentrations and longer incubation period of ionic gold. Here, we describe a simplistic method of intracellular biomineralization to produce plasmonic gold nanoparticles at micromolar concentrations within 30 min of application utilizing polyethylene glycol as delivery vector for ionic gold. We have characterized this process for intracellular gold nanoparticle formation, which progressively accumulates proteins as the ionic gold clusters migrate to the nucleus. This nano-vectorized application of ionic gold emphasizes its potential biomedical opportunities while reducing the quantity of ionic gold and required incubation time. To demonstrate its biomedical potential, we further induce in-situ biosynthesis of gold nanoparticles within MCF7 tumor mouse xenografts which is followed by its photothermal remediation.

Temperature sensitive p(N-isopropylacrylamide-co-acrylic acid) modified gold nanoparticles for trans-arterial embolization and angiography

2017 ◽  
Vol 5 (5) ◽  
pp. 907-916 ◽  
Author(s):  
Yiming Liu ◽  
Xiaole Peng ◽  
Kun Qian ◽  
Yingying Ma ◽  
Jiangshan Wan ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Acrylic Acid ◽  
Blood Vessel ◽  
Arterial Embolization ◽  
Temperature Sensitive ◽  
X Ray ◽  
X Ray Imaging

Temperature-sensitive in situ hydrogels of GNP@PNA nanomedicine achieve good blood-vessel embolization and X-ray imaging on rabbits.

scholarly journals Shape-Controlled Generation of Gold Nanoparticles Assisted by Dual-Molecules: The Development of Hydrogen Peroxide and Oxidase-Based Biosensors

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chifang Peng ◽  
Xiaohui Duan ◽  
Zhengjun Xie ◽  
Chunli Liu
Keyword(s):  
Gold Nanoparticles ◽  
Sodium Citrate ◽  
Chloroauric Acid ◽  
One Pot ◽  
Naked Eye ◽  
Different Shapes ◽  
Shape Controlled ◽  
Ethanesulfonic Acid ◽  
Mediated Reduction ◽  
Anisotropic Metal

With the assist of dual-molecules, 2-(N-morpholino)ethanesulfonic acid (MES) and sodium citrate, gold nanoparticles (GNPs) with different shapes can be generated in the H2O2-mediated reduction of chloroauric acid. This one-pot reaction can be employed to sensitively detect H2O2, probe substrates or enzymes in oxidase-based reactions as well as prepare branched GNPs controllably. By the “naked eye,” 20 μM H2O2, 0.1 μM glucose, and 0.26 U/mL catalase could be differentiated, respectively. By spectrophotometer, the detected limits of H2O2, glucose, and catalase were 1.0 μM, 0.01 μM, and 0.03 U/mL, respectively, and the detection linear ranges for them were 5.0–400 μM, 0.01–0.3 mM, and 0.03–0.78 U/mL, respectively. The proposed “dual-molecules assist” strategy probably paves a new way for the fabrication of nanosensors based on the growth of anisotropic metal nanoparticles, and the developed catalase sensor can probably be utilized to fabricate ultrasensitive ELISA methods for various analytes.

CONTROLLING THE SIZE AND SIZE DISTRIBUTION OF GOLD NANOPARTICLES: A DESIGN OF EXPERIMENT STUDY

2012 ◽  
Vol 11 (02) ◽  
pp. 1250023 ◽  
Author(s):  
DHIRAJ KUMAR ◽  
BRIAN J MEENAN ◽  
ISHA MUTREJA ◽  
RAECHELLE D'SA ◽  
DORIAN DIXON
Keyword(s):  
Gold Nanoparticles ◽  
Size Distribution ◽  
Design Of Experiment ◽  
Metallic Nanoparticles ◽  
Sodium Citrate ◽  
Chloroauric Acid ◽  
Production Volume ◽  
Synthesis Of Nanoparticles ◽  
Potential Applications ◽  
Poly Ethylene

The Turkevich method is the oldest and most widely employed protocol for the production of colloidal gold. Gold nanoparticles are nontoxic in nature and have potential applications in various biomedical fields including drug delivery and bioimaging. These metallic nanoparticles can be functionalized with drugs, targeting ligands such as tumor necrosis factor and groups (e.g., Poly ethylene glycol) to provide shielding from undesired immune responses. In this study we investigate the influence of process variables on the synthesis of nanoparticles by the reduction of chloroauric acid ( HAuCl4 ) solution with sodium citrate. A design of experiment (DoE) approach was used to investigate the influence of production volume, temperature, stirring rate and sodium citrate concentration on the physical properties of the nanoparticles namely size, size distribution, zeta potential and UV-Vis characteristics. The study showed that the relative amount of sodium citrate added ( Au /citrate mole ratio) had a significant effect on the size, poly dispersity index (PDI), the number of peaks in the size distribution and the position of Lambda max in the UV-Vis spectra. By varying the Au /Citrate ratio it is possible to synthesize particles with average diameters from 20 to 80 nm. However, the use of low amounts of sodium citrate in order to produce particles larger than ~35 nm tends to result in a wide bimodal size distribution.

Controlled Nano-Oxide Layer Coating on Fine Particles with Multiple Optical-Electrical Functions

2006 ◽  
Vol 313 ◽  
pp. 37-42
Author(s):  
Wen Cheng J. Wei ◽  
B.Y. Yu ◽  
J.F. Li ◽  
C.S. Chen
Keyword(s):  
Colloidal Stability ◽  
Fine Particles ◽  
Fine Tuning ◽  
Nano Particles ◽  
Composite Particles ◽  
Surface Charging ◽  
Nano Oxide ◽  
Shell Composite ◽  
Processing Steps ◽  
Layer Coating

SiO2 core/TiO2 shell composite particles were synthesized by four different heterogeneous coagulation techniques. The configurations of the composite particles and the microstructure of assembly were characterized by SEM and TEM. The colloidal stability of nano-particles was also computer-simulated by a discrete element method (DEM) in consideration of Brownian motion occurring on the nano-particles. The results indicated that uniform adsorption of the fine particle absolutely needed fine tuning of surface charging conditions and processing steps.

Characterization of Micro-Valves for Lab-on-Chip Device

2007 ◽  
Author(s):  
S. Dutta ◽  
D. Banerjee
Keyword(s):  
Water Quality ◽  
Molecular Recognition ◽  
Reaction Chamber ◽  
Nano Particles ◽  
Reaction Products ◽  
Lab On Chip ◽  
External Power Source ◽  
Gold Nano Particles ◽  
On Chip

The objective of this study is to develop a portable hand held diagnostics platform for monitoring pollutants and water quality testing. We are developing a lab-on-chip (LOC) device for in-situ synthesis of gold nano-particles and for using a colorimetric peptide assay for water quality monitoring. The gold nano-particles are synthesized in-situ in our experiments. The gold nano-particles exhibit various optical properties due to their Surface Plasmon Resonance (SPR). These stabilized mono-disperse gold nano-particles are coated with bio-molecular recognition motifs on their surfaces. The stabilization and functionalization with bio-molecular recognition motif provides flexibility for various applications. For example, the gold nano-particles synthesized by this process are tested for their ability to be recognized by a surface coated with anti-Flg antibodies. The LOC consists of micro-wells housing different reagents and samples that feed to a common reaction chamber. The reaction products are delivered to several waste chambers in a pre-defined sequence to enable subsequent reagents/ samples to flow into the reaction chamber. Passive flow actuation is obtained by capillary driven flow (wicking). Dissolvable micro-structures are used as passive micro-valves that actuate at predefined intervals and do not require any external power source for actuation. The microfluidic chip (LOC) and the dissolvable microstructures are fabricated using soft lithography techniques. The passive valves are incorporated into the microfluidics platform by novel micro-fabrication and bonding techniques.

In situ high temperature TEM observation of interaction between multi-walled carbon nanotube and in situ deposited gold nano-particles

Microscopy ◽  
2005 ◽  
Vol 54 (5) ◽  
pp. 461-465 ◽  
Author(s):  
Takeo Kamino ◽  
Toshie Yaguchi ◽  
Mitsuru Konno ◽  
Takahito Hashimoto
Keyword(s):  
High Temperature ◽  
Carbon Nanotube ◽  
Nano Particles ◽  
Multi Walled Carbon Nanotube ◽  
Gold Nano Particles
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