Seed-Mediated Synthesis of Branched Gold Nanocrystals Derived from the Side Growth of Pentagonal Bipyramids and the Formation of Gold Nanostars

2009 ◽  
Vol 21 (1) ◽  
pp. 110-114 ◽  
Author(s):  
Hsin-Lun Wu ◽  
Chiu-Hua Chen ◽  
Michael H. Huang
Keyword(s):  
Gold Nanocrystals ◽  
Gold Nanostars ◽  
Seed Mediated

scholarly journals Covalently capped seed-mediated growth: a unique approach toward hierarchical growth of gold nanocrystals

Nanoscale ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 6478-6481 ◽  
Author(s):  
Youju Huang ◽  
Anirban Dandapat ◽  
Dong-Hwan Kim
Keyword(s):  
Gold Nanostructures ◽  
Gold Nanocrystals ◽  
Unique Approach ◽  
Different Shapes ◽  
Seed Mediated ◽  
Growth Approach

A new 600 dpi in TIF format)??>method is proposed for synthesizing hierarchical gold nanostructures in different shapes using the covalently capped seed-mediated growth approach.

Seed-Mediated Synthesis of Monodisperse Concave Trisoctahedral Gold Nanocrystals with Controllable Sizes

2010 ◽  
Vol 114 (25) ◽  
pp. 11119-11126 ◽  
Author(s):  
Yue Yu ◽  
Qingbo Zhang ◽  
Xianmao Lu ◽  
Jim Yang Lee
Keyword(s):  
Gold Nanocrystals ◽  
Seed Mediated

scholarly journals Seed-Mediated Growth of Gold Nanocrystals: Changes to the Crystallinity or Morphology as Induced by the Treatment of Seeds with a Sulfur Species

2014 ◽  
Vol 118 (49) ◽  
pp. 14132-14139 ◽  
Author(s):  
Yiqun Zheng ◽  
Ming Luo ◽  
Jing Tao ◽  
Hsin-Chieh Peng ◽  
Dehui Wan ◽  
...  
Keyword(s):  
Sulfur Species ◽  
Gold Nanocrystals ◽  
Seed Mediated

scholarly journals One-Pot, Surfactant-Free Synthesis of Gold Nanostars and Evaluation of Their Antibacterial Effects against Propionibacterium acnes

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Phat Trong Huynh ◽  
Giang Dang Nguyen ◽  
Khanh Thi Le Tran ◽  
Thu Minh Ho ◽  
Bich Thi Duong ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Propionibacterium Acnes ◽  
Acne Vulgaris ◽  
Nanoparticle Synthesis ◽  
Plate Count ◽  
Diffusion Method ◽  
One Pot ◽  
Gold Nanostars ◽  
Seed Mediated

Anisotropic gold nanoparticles, especially gold nanostars, are used in many fields of biomedical applications such as sensing, targeted drug delivery, and diagnostic and photothermal therapy. In this study, we introduced a novel application of gold nanostars as an antimicrobial agent. While spherical gold nanoparticles have an inappreciable effect, gold nanostars exhibit significant antibacterial activity. Besides, the seed-mediated method, a conventional technique for preparing gold nanostars, is rather complex and toxic to human and environment due to unsafe synthesized materials such as surfactants and reducers. In recent years, green chemistry for nanoparticle synthesis is attractive because of its advantages. Instead of the seed-mediated procedure, we present a facile and green procedure to synthesize gold nanostars using ascorbic acid as a reductant and chitosan as a directing-growth agent. The influences of reacting parameters were evaluated to determine the optimal conditions. Star-shaped gold nanoparticles were successfully synthesized with average size tunning from 137.0 ± 20.7   nm to 281.9 ± 25.8   nm of the core and 14.0 ± 4.4   nm to 54.2 ± 11.9   nm of branches. Antibacterial activity against Propionibacterium acnes of gold nanostars was also investigated. Propionibacterium acnes is one of the main reasons causing acne vulgaris. The antibacterial test was evaluated by the plate count and well diffusion method. The results showed a significant effect that gold nanostars could be the prospective agent for replacing antibiotics in acne treatment.

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.

Synthesis and Characterization of Silver Nanoplates by a Seed-mediated Method

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Trisodium Citrate ◽  
Synthesis And Characterization ◽  
Silver Nanoplates ◽  
Seed Mediated

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.

Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

2019 ◽  
Author(s):  
Theodoros Tsoulos ◽  
Supriya Atta ◽  
Maureen Lagos ◽  
Michael Beetz ◽  
Philip Batson ◽  
...  
Keyword(s):  
Single Particle ◽  
Structural Complexity ◽  
Field Enhancement ◽  
Hot Electron ◽  
Structure Property ◽  
Plasmon Band ◽  
Gold Nanostars ◽  
Wide Range ◽  
Particle Level ◽  
Spectrally Resolved

<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

The interact of photons of light with photonic gold nanocrystals prepared using eriocephalus punctulatus assisted poly-yol route

Optik ◽  
2020 ◽  
Vol 224 ◽  
pp. 165543
Author(s):  
L.A.M. Al-Sagheer ◽  
Ahmed Alshehrie ◽  
W. Elsayed
Keyword(s):  
Gold Nanocrystals
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