scholarly journals Synthesis of Porous Polydimethylsiloxane Gold Nanoparticles Composites by a Single Step Laser Ablation Process

2021 ◽  
Vol 22 (22) ◽  
pp. 12155
Author(s):  
Mariapompea Cutroneo ◽  
Vladimir Havranek ◽  
Anna Mackova ◽  
Petr Malinsky ◽  
Letteria Silipigni ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Au Nanoparticles ◽  
Metal Salt ◽  
Single Step ◽  
Curing Agent ◽  
Step Method ◽  
Au Nps ◽  
Liquid Polymer ◽  
Vis Spectroscopy

Typically, polymeric composites containing nanoparticles are realized by incorporating pre-made nanoparticles into a polymer matrix by using blending solvent or by the reduction of metal salt dispersed in the polymeric matrix. Generally, the production of pre-made Au NPs occurs in liquids with two-step processes: producing the gold nanoparticles first and then adding them to the liquid polymer. A reproducible method to synthetize Au nanoparticles (NPs) into polydimethylsiloxane (PDMS) without any external reducing or stabilizing agent is a challenge. In this paper, a single-step method is proposed to synthetize nanoparticles (NPs) and at the same time to realize reproducible porous and bulk composites using laser ablation in liquid. With this single-step process, the gold nanoparticles are therefore produced directly in the liquid polymer. The optical properties of the suspensions of AuNPs in distilled water and in the curing agent have been analyzed by the UV-VIS spectroscopy, employed in the transmission mode, and compared with those of the pure curing agent. The electrical dc conductivity of the porous PDMS/Au NPs nanocomposites has been evaluated by the I–V characteristics. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis have monitored the composition and morphology of the so-obtained composites and the size of the fabricated Au nanoparticles. Atomic force microscopy (AFM) has been used to determine the roughness of the bulk PDMS and its Au NP composites.

Size Reduction of Gold Nanoparticles by Pulsed Laser Ablation and Re-Irradiation in Water Media

2011 ◽  
Vol 695 ◽  
pp. 174-177 ◽  
Author(s):  
Pichitchai Pimpang ◽  
Duangmanee Wongratanaphisan ◽  
Atcharawan Gardchareon ◽  
Supab Choopun
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Zeta Potential ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Size Reduction ◽  
Au Nps ◽  
Vis Spectroscopy ◽  
Water Media ◽  
Cover Slide

Gold nanoparticles (Au NPs) were prepared by using pulsed laser ablation with and without cover slide. The cover slide was used to confine atoms/ions in order to reach supersaturation condition. The obtained Au NPs were investigated by UV-vis spectroscopy, transmission electron microscopy (TEM), and zeta potential measurement. The absorbance spectra exhibited its absorption peak at around 520 nm for both Au NPs ablating with and without cover slide. It was found that Au NPs ablating with cover slide exhibited smaller size and size distribution (10.6 ± 5.9 nm) than those of without cover slide (34.1 ± 21.5 nm) at laser power of 5.00 mJ/pulse. This is due to supersaturation effect and re-irradiation effect caused by cover slide that trapped atoms/ions of gold and trapped Au NPs, respectively. Also, the zeta potential of Au NPs had a negative value suggesting negative surface charge. The lowest zeta potential was observed for Au NPs ablating with cover slide at 5.00 mJ/pulse and it was in consistent with an observation of the highest pH value. In addition, the Au NPs ablating with cover slide at 5.00 mJ/pulse showed the least change with time indicating the most stable Au NPs which was in consistent with the lowest zeta potential results. Thus, pulsed laser re-irradiation could be used for size reduction of Au NPs prepared by pulsed laser ablation in water media.

scholarly journals Effects of Different Surfactant Charges on the Formation of Gold Nanoparticles by the LASiS Method

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2937
Author(s):  
Muhammad Zulfajri ◽  
Wei-Jie Huang ◽  
Genin-Gary Huang ◽  
Hui-Fen Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Laser System ◽  
Synthesis Process ◽  
Au Nps ◽  
Laser Fluences ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
532 Nm

The laser ablation synthesis in solution (LASiS) method has been widely utilized due to its significant prospects in laser microprocessing of nanomaterials. In this study, the LASiS method with the addition of different surfactant charges (cationic CTAB, nonionic TX-100, and anionic SDS) was used to produce Au NPs. An Nd:YAG laser system at 532 nm excitation with some synthetic parameters, including different laser fluences, ablation times, and surfactant concentrations was performed. The obtained Au NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, and zeta potential analyzer. The Au NPs exhibited the maximum absorption peak at around 520 nm for all samples. The color of Au NPs was changed from red to reddish by increasing the laser fluence. The surfactant charges also played different roles in the Au NPs’ growth during the synthesis process. The average sizes of Au NPs were found to be 8.5 nm, 5.5 nm, and 15.5 nm with the medium containing CTAB, TX-100, and SDS, respectively. Besides, the different surfactant charges induced different performances to protect Au NPs from agglomeration. Overall, the SDS and CTAB surfactants exhibited higher stability of the Au NPs compared to the Au NPs with TX-100 surfactant.

Sensitive Hg2+ Ion Detection Using Metal Enhanced Fluorescence of Novel Polyvinyl Pyrrolidone (PVP)-Templated Gold Nanoparticles

2018 ◽  
Vol 72 (11) ◽  
pp. 1645-1652 ◽  
Author(s):  
Kailong Dong ◽  
Jiasheng Zhou ◽  
Taiqun Yang ◽  
Shan Dai ◽  
Hao Tan ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Au Nanoparticles ◽  
Polyvinyl Pyrrolidone ◽  
Quenching Mechanism ◽  
Ion Detection ◽  
Enhanced Fluorescence ◽  
Metal Enhanced Fluorescence ◽  
One Pot ◽  
Au Nps

In this study, we report a straightforward strategy for Hg2+ ion detection. Fluorescent Au nanoparticles (NPs) were one-pot synthesized using a polymer (polyvinyl pyrrolidone [PVP]) as both capping and fluorescence agent. The as-synthesized PVP-Au NPs showed a remarkably rapid response selectively for Hg2+ ions compared to 14 other metal ions. The detection limit of Hg2+ was estimated at 100 nM. We discuss the emission and quenching mechanism of the PVP-Au NPs, the former being attributed to metal enhanced fluorescence and the latter being related to static quenching by Hg2+. The fluorescence of PVP-Au NPs offers an efficient and reliable strategy for Hg2+ ions detection. They therefore have a great potential for applications in health and environmental monitoring.

scholarly journals A rapid and ultrasensitive colorimetric biosensor based on aptamer functionalized Au nanoparticles for detection of saxitoxin

RSC Advances ◽  
2020 ◽  
Vol 10 (26) ◽  
pp. 15293-15298
Author(s):  
Le Qiang ◽  
Yu Zhang ◽  
Xin Guo ◽  
Yakun Gao ◽  
Yingkuan Han ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Colorimetric Sensor ◽  
Quantitative Detection ◽  
Au Nps

We demonstrate a facile and ultrasensitive colorimetric sensor based on gold nanoparticles (Au NPs) and aptamer (Au NPs-aptamer biosensor) for specific and quantitative detection of STX.

Preparation of Au nanoparticles by Anthemis xylopoda flowers aqueous extract and their application for alkyne/aldehyde/amine A3-type coupling reactions

RSC Advances ◽  
2015 ◽  
Vol 5 (57) ◽  
pp. 46240-46246 ◽  
Author(s):  
Mahmoud Nasrollahzadeh ◽  
S. Mohammad Sajadi
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Aqueous Extract ◽  
Au Nanoparticles ◽  
Coupling Reactions ◽  
Au Nps ◽  
Type Coupling

This paper reports on the green synthesis of gold nanoparticles (Au NPs) by Anthemis xylopoda flowers aqueous extract without the addition of surfactant agents and their application as stable catalysts for the synthesis of propargylamines.

scholarly journals Successful Green Synthesis of Gold Nanoparticles using a Corchorus olitorius Extract and Their Antiproliferative Effect in Cancer Cells

2018 ◽  
Vol 19 (9) ◽  
pp. 2612 ◽  
Author(s):  
Eman Ismail ◽  
Aliyah Saqer ◽  
Eman Assirey ◽  
Arshi Naqvi ◽  
Rawda Okasha
Keyword(s):  
Gold Nanoparticles ◽  
Metal Salt ◽  
Human Cancer ◽  
Reaction Medium ◽  
Breast Adenocarcinoma ◽  
Organic Layer ◽  
Gravimetric Analysis ◽  
Corchorus Olitorius ◽  
Au Nps

A facile bottom-up “green” synthetic route of gold nanoparticles (Au NPs) is described, using a leaf extract of the Malvaceae plant Corchorus olitorius as a reducing and stabilizing agent. The size and shape of the obtained nanoparticles were modulated by varying the amounts of the metal salt and the broth extract in the reaction medium. Only one hour was required for the complete conversion to Au NPs, suggesting that the reaction rate was higher or comparable to those of nanoparticles synthesized by chemical methods. The obtained nanoparticles were characterized by UV–visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and thermal gravimetric analysis (TGA). While infrared spectroscopy was employed to characterize the various functional groups in the organic layer that stabilized the particles, TEM images were used to optimize the conditions for NPs growth. A low concentration of the C. olitorius extract yielded mixed triangular and hexagonal shapes; in contrast, quasi-spherical shapes of Au NPs with an average size of 37–50 nm were obtained at a higher extract broth concentration. The Au NPs displayed Surface Plasmon Resonance (SPR) bands at 535 nm. An in vitro cytotoxic assay of the biocompatible Au NPs revealed a strong cytotoxic activity in three human cancer cell lines, namely, colon carcinoma HCT-116, hepatocellular carcinoma HepG-2, and breast adenocarcinoma MCF-7. In-silico bioactivity, drug-likeness, and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) predictions were conducted in order to examine the pharmacokinetic behavior of the compounds present in the C. olitorius extract.

scholarly journals Single-step assembly of gold nanoparticles into plasmonic colloidosomes at the interface of oleic acid nanodroplets

2021 ◽  
Vol 3 (1) ◽  
pp. 198-205
Author(s):  
José M. López-de-Luzuriaga ◽  
Miguel Monge ◽  
Javier Quintana ◽  
María Rodríguez-Castillo
Keyword(s):  
Gold Nanoparticles ◽  
Oleic Acid ◽  
Self Assembly ◽  
Single Step ◽  
The Self ◽  
Au Nps ◽  
Spherical Gold Nanoparticles

Plasmonic gold colloidosomes (Au CSs) of sub-200 nm size are formed by the self-assembly of spherical gold nanoparticles (Au NPs) of ca. 4 nm size at the interface of oleic acid (OA) nanodroplets formed in n-hexane.

A Single Step Fast Track Methodology for In-Situ Detection of Hazardous Melamine by Using Highly Sensitive Polyphenolics Modified Nanogold Probe

2019 ◽  
Vol 19 (11) ◽  
pp. 7229-7235
Author(s):  
Anila Arshad ◽  
Raheel Akram ◽  
Shahid Iqbal Rana ◽  
Ghulam Hussain ◽  
Sami Ullah Dar ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Fast Track ◽  
Raw Milk ◽  
Single Step ◽  
Hydroxyl Group ◽  
Time Saving ◽  
Au Nps ◽  
Highly Sensitive ◽  
Capping Ligands ◽  
In Situ Detection

A single step fast track method is proposed to determine melamine based on strong hydrogen bonding between exocyclic amine group in melamine moiety and hydroxyl group of tannic acid (TA); acting as reducing and functionalizing agent for synthesis of gold nanoparticles (Au NPs). The proposed strategy is facile and highly time saving; as the detection of melamine with labelfree gold nanoparticles was accomplished within five minutes. The colorimetric probe exhibits high detection limit of 8 nM for melamine determination in raw milk, which is very low as compared to other capping ligands employed for Au NPs such as borohydride, citrate and 3,5-dihydroxybenzoic acid. The results show a highly sensitive linear range (0.03–2.5 μM) between absorption ratio and concentration of melamine with a correlation coefficient of 0.991. Proposed methodology is proven effective for on-site screening without using costly instrumentation.

scholarly journals Theranostic Nanoplatforms of Thiolated Reduced Graphene Oxide Nanosheets and Gold Nanoparticles

2020 ◽  
Vol 10 (16) ◽  
pp. 5529 ◽  
Author(s):  
Pascal Tomasella ◽  
Vanessa Sanfilippo ◽  
Carmela Bonaccorso ◽  
Lorena Maria Cucci ◽  
Giuseppe Consiglio ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Density Functional ◽  
Metal Salt ◽  
Colorimetric Assay ◽  
Neuroblastoma Cells ◽  
Human Neuroblastoma ◽  
Force Microscopy ◽  
Vis Spectroscopy

In this study, graphene oxide (GO) and reduced-thiolated GO (rGOSH) were used as 2D substrate to fabricate nanocomposites with nanoparticles of gold nanospheres (AuNS) or nanorods (AuNR), via in situ reduction of the metal salt precursor and seed-mediated growth processes. The plasmonic sensing capability of the gold-decorated nanosheets were scrutinized by UV-visible (UV-VIS) spectroscopy. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analyses (TGA), and atomic force microscopy (AFM) were performed in order to prove the actual reduction that occurred concomitantly with the thiolation of GO, the increase in the hydrophobic character as well as the size, and preferential gathering of the gold nanoparticles onto the nanosheet substrates, respectively. Moreover, the theoretical electronic and infrared absorption (UV-VIS and IR) spectra were calculated within a time-dependent approach of density functional theory (DFT). Eventually, in vitro cellular experiments on human neuroblastoma cells (SH-SY5Y line) were carried out in order to evaluate the nanotoxicity of the nanocomposites by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction (MTT) colorimetric assay. Results pointed out the promising potential of these hybrids as plasmonic theranostic platforms with different hydrophilic or hydrophobic features as well as cytotoxic effects against cancer cells.

Highly stable Au nanoparticles with double hydrophilic block copolymer templates: correlation between structure and stability

2017 ◽  
Vol 8 (31) ◽  
pp. 4528-4537 ◽  
Author(s):  
Eunyong Seo ◽  
Sang-Ho Lee ◽  
Sangho Lee ◽  
Soo-Hyung Choi ◽  
Craig J. Hawker ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Block Copolymer ◽  
Acrylic Acid ◽  
Colloidal Stability ◽  
Au Nanoparticles ◽  
Synthetic Method ◽  
Au Nps ◽  
Double Hydrophilic Block Copolymers ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

We herein report a facile synthetic method for preparing gold nanoparticles (Au NPs) with superior colloidal stability using a series of double hydrophilic block copolymers (DHBC), poly(ethylene oxide)-block-poly(acrylic acid) (PEO-b-PAA), as a template (Au@DHBC NPs).

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