Effect of Gold Nanoparticles Size on Detection of Methylphosphonic Acid Hydrolysis Product of Nerve Agent

2021 ◽  
Vol 25 (7) ◽  
pp. 1-7
Author(s):  
Fellyzra Elvya Pojol ◽  
Buong Woei Chieng ◽  
Keat Khim Ong ◽  
Rashid Jahwarhar Izuan Abd ◽  
Mohd Junaedy Osman ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Inverse Method ◽  
Direct Method ◽  
Hydrolysis Product ◽  
Spherical Shape ◽  
Methylphosphonic Acid ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Citrate Reduction ◽  
Chloride Trihydrate

Citrate reduction of gold (III) chloride trihydrate (HAuCl4) is commonly used method to synthesise citrate-capped gold nanoparticles (cit-AuNPs). In this study, the sequence of reagents addition was modified (“inverse” method) to synthesise smaller size of cit-AuNPs than the standard Turkevich method (“direct” method). Ultraviolet-visible spectroscopy (UV-vis) and field emission transmission electron microscopy (FETEM) confirmed the formation of cit-AuNPs. The cit-AuNPs synthesized using “inverse” method are smaller in size (14.0 ± 3.03 nm) with uniform spherical shape compared to “direct” method (23.5 ± 7.52 nm). Smaller particles size of cit-AuNPs provide higher efficiency and sensitivity for detection of methylphosphonic acid (MPA) via colorimetric incorporated with image processing with a linear range from 2.5 to 12.5 mM and a low detection limit of 6.28 mM at shorter detection period (24 to 30 s).

Biosynthesis of Gold Nanoparticles with Serratia marcescens Bacteria

2015 ◽  
Vol 1132 ◽  
pp. 19-35
Author(s):  
S.O. Dozie-Nwachukwu ◽  
J.D. Obayemi ◽  
Y. Danyo ◽  
G. Etuk-Udo ◽  
N. Anuku ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Serratia Marcescens ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Color Changes ◽  
Transmission Electron ◽  
Helium Ion ◽  
Ph Conditions ◽  
Uv Visible ◽  
Ion Microscopy

This paper presents the biosynthesis of gold nanoparticles from the bacteria, Serratia marcescens.The intra-and extra-cellular synthesis of gold nanoparticles is shown to occur over a range of pH and incubation times in cell-free exracts and biomass ofserratia marcescensthat were reacted with 2.5mM Tetrachloroauric acid (HAuCl4). The formation of gold nanoparticles was identified initially via color changes from yellow auro-chloride to shades of red or purple in gold nanoparticle solutions. UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDS), Helium Ion Microscopy (HIM) and Dynamic Light Scattering (DLS) were also used to characterize gold nanoparticles produced within a range of pH conditions. The results show clearly that the production of gold nanoparticles from cell-free extracts require shorter times than the production of gold nanoparticles from the biomass.

scholarly journals Green Nanoparticles for Mosquito Control

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Namita Soni ◽  
Soam Prakash
Keyword(s):  
Gold Nanoparticles ◽  
Mosquito Control ◽  
Spherical Shape ◽  
Probit Analysis ◽  
Bark Extract ◽  
Green Method ◽  
Silver And Gold Nanoparticles ◽  
Transmission Electron ◽  
Uv Visible ◽  
Filariasis Vector

Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag) and gold (Au) nanoparticles (NPs) were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum) (C. zyelanicumorC. verumJ. Presl). Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vectorAnopheles stephensiand filariasis vectorCulex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs). The larvae ofAn. stephensiwere found highly susceptible to the synthesized AgNPs and AuNPs than theCx. quinquefasciatus. These results suggest that theC. zeylanicumsynthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito.

scholarly journals pH Dependence of Size Control in Gold Nanoparticles Synthesized at Room Temperature

2018 ◽  
Vol 34 (5) ◽  
pp. 2305-2312 ◽  
Author(s):  
Shohifah Annur ◽  
Sri Juari Santosa ◽  
Nurul Hidayat Aprilita
Keyword(s):  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Room Temperature ◽  
Ph Dependence ◽  
Size Control ◽  
Spherical Shape ◽  
Alkaline Condition ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Spherical Gold Nanoparticles

We have developed the spherical gold nanoparticles (AuNPs) with different size at room temperature using L-ascorbic acid as a reducing agent. Controlling pH of L-ascorbic acid from 2.0 to 10.0 caused the decreasing of AuNPs size when measured using particle size analyzer. The alkaline condition leads to increase the reactivity of L-ascorbic acid even at room temperature. The homogeneous AuNPs were achieved even the synthesis was conducted at different pH of L-ascorbic acid (pH 2.0 to 12.0). The investigation using Transmission Electron Microscopy (TEM) confirmed that AuNPs performed a spherical shape. SEM-EDX measurement performed a strong characteristic peak of Au appeared at 2.0 keV. This research could be used to control of AuNPs size when synthesized at room temperature. The AuNPs obtained at optimum condition was stable up to 3 months.

scholarly journals Synthesis and Ultraviolet Visible Spectroscopy Studies of Chitosan Capped Gold Nanoparticles and Their Reactions with Analytes

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Norfazila Mohd Sultan ◽  
Mohd Rafie Johan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Absorption Spectra ◽  
Zinc Sulphate ◽  
Monosodium Glutamate ◽  
Target Material ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Spectroscopy Studies

Gold nanoparticles (AuNPs) had been synthesized with various molarities and weights of reducing agent, monosodium glutamate (MSG), and stabilizer chitosan, respectively. The significance of chitosan as stabilizer was distinguished through transmission electron microscopy (TEM) images and UV-Vis absorption spectra in which the interparticles distance increases whilst retaining the surface plasmon resonance (SPR) characteristics peak. The most stable AuNPs occurred for composition with the lowest (1 g) weight of chitosan. AuNPs capped with chitosan size stayed small after 1 month aging compared to bare AuNPs. The ability of chitosan capped AuNPs to uptake analyte was studied by employing amorphous carbon nanotubes (α-CNT), copper oxide (Cu2O), and zinc sulphate (ZnSO4) as the target material. The absorption spectra showed dramatic intensity increased and red shifted once the analyte was added to the chitosan capped AuNPs.

Effect of pH on the Green Synthesis of Silver Nanoparticles through Reduction with Pistiastratiotes L. Extract

2015 ◽  
Vol 1131 ◽  
pp. 223-226 ◽  
Author(s):  
Pranlekha Traiwatcharanon ◽  
Kriengkri Timsorn ◽  
Chatchawal Wongchoosuk
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Spherical Shape ◽  
Silver Ions ◽  
Basic Medium ◽  
Metallic Silver ◽  
Visible Spectroscopy ◽  
Ag Nps ◽  
Transmission Electron ◽  
Effects Of Ph

In this work, we have presented the green synthesis of silver nanoparticles (Ag-NPs) using extracts of Pistiastratiotes L. as reducing agent. The silver nitrate (AgNO3) solutions were used as precursor. The experiments were performed under irradiation with a light that can help to increase the activation for reduction of silver ions (Ag+) to metallic silver (Ag0). The effects of pH on the nature of Ag-NPs have been systematically studied by using ultraviolet-visible spectroscopy (UV-Vis) and transmission electron microscopy (TEM). The results show that the synthesis of Ag-NPs in acidic medium gives smaller size than that in basic medium. A number of synthesized Ag-NPs increase with increasing the concentrations of acidic/basic medium. All synthesized Ag-NPs have spherical shape.

scholarly journals Green Synthesis of Gold Nanoparticles Using Aqueous Extract ofGarcinia mangostanaFruit Peels

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Kar Xin Lee ◽  
Kamyar Shameli ◽  
Mikio Miyake ◽  
Noriyuki Kuwano ◽  
Nurul Bahiyah Bt Ahmad Khairudin ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Spherical Shape ◽  
Garcinia Mangostana ◽  
Au Nps ◽  
Synthetic Materials ◽  
Transmission Electron ◽  
Environmentally Safe ◽  
Diffraction Peaks ◽  
Gold Metal ◽  
Peel Extract

The synthesis of gold nanoparticles (Au-NPs) is performed by the reduction of aqueous gold metal ions in contact with the aqueous peel extract of plant,Garcinia mangostana(G. mangostana). An absorption peak of the gold nanoparticles is observed at the range of 540–550 nm using UV-visible spectroscopy. All the diffraction peaks at 2θ= 38.48°, 44.85°, 66.05°, and 78.00° that index to (111), (200), (220), and (311) planes confirm the successful synthesis of Au-NPs. Mostly spherical shape particles with size range of 32.96 ± 5.25 nm are measured using transmission electron microscopy (TEM). From the FTIR results, the peaks obtained are closely related to phenols, flavonoids, benzophenones, and anthocyanins which suggest that they may act as the reducing agent. This method is environmentally safe without the usage of synthetic materials which is highly potential in biomedical applications.

scholarly journals Gold nanoparticles from Celastrus hindsii and HAuCl4: Green synthesis, characteristics, and their cytotoxic effects on HeLa cells

2021 ◽  
Vol 10 (1) ◽  
pp. 73-84
Author(s):  
Xuan-Truong Mai ◽  
Minh-Chien Tran ◽  
Anh-Quan Hoang ◽  
Phuc Dang-Ngoc Nguyen ◽  
Thi-Hiep Nguyen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Hela Cells ◽  
Particle Diameter ◽  
Spherical Shape ◽  
Natural Antioxidants ◽  
Cytotoxic Effects ◽  
Au Nps ◽  
Transmission Electron ◽  
Dose Dependent

Abstract The extract from Celastrus hindsii (C. hindsii), a plant that naturally grows in the forests of several provinces of Vietnam, has been traditionally used as an alternative medicine for the treatment of inflammation because of its anticancer and antitumor properties. This study reported the green synthesis of stable gold nanoparticles (Au-NPs) derived from HAuCl4 using the extract of C. hindsii as reducing and capping agents. Their particle size could be controlled by adjusting the ratio of the extract to HAuCl4 solution used (1.25%, 2.5%, 3.75%, 5.0%, and 6.25%). The optimal ratio of the extract was 3.75% (Au-NPs-3.75%). The X-ray powder diffraction analysis demonstrated that the Au-NPs was successfully synthesized. Fourier-transform infrared spectroscopy result indicated the possible presence of phenolic acids and flavonoids (acting as reducing agents and potential natural antioxidants). Transmission electron microscopy images showed that the particle diameter of Au-NPs-3.75% varied between 13 and 53 nm (average: ∼30 nm) in its spherical shape. The biosynthesized Au-NPs-3.75% exhibited dose-dependent cytotoxicity against HeLa cells, and the inhibitory concentration (IC50) was 12.5 µg/mL at 48 h. Therefore, Au-NPs that were synthesized from environmentally friendly method without the presence of potentially toxic chemicals were highly possible in biomedical applications.

Preparation and Characterization of Silver and Gold Nanoparticles and Study Influence on Physical Properties of PVA/PVP nanocomposites

2017 ◽  
Vol 13 (1) ◽  
pp. 4628-4639
Author(s):  
A. M. Abdelghany ◽  
Mahrous. S. Meikhail ◽  
A. A. ALdhabi
Keyword(s):  
Gold Nanoparticles ◽  
Spherical Shape ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Au Nps ◽  
Silver And Gold Nanoparticles ◽  
Plant Extraction ◽  
Chenopodium Murale ◽  
Transmission Electron

Gold nanoparticles (Au NPs) and Silver nanoparticles (Ag NPs) ware prepared by “green” synthesis extraction using the Chenopodium murale leaf extract, the obtained (Ag NPs and Au NPs) were investigated by UV/Vis. absorption spectroscopy, transmission electron microscopy, Zetasizer, XRD. The plant extraction leads to produce nanoparticles of spherical shape with size range from 4 to 22 nm. Polyvinyl alcohol (PVA) and polyvinyl Pyrolidone (PVP) blend with mixed silver and gold nanoparticles were prepared by casting method. Amorphous feather of doping polymers blend was characterized by X-ray diffraction. Significant changes within the polymer matrix were monitored from infrared spectroscopy which indicates the interaction between polymer blend and mixed nanoparticles. Both indirect and direct optical energy gaps are calculated and discussed.

Controlling the Absorption of Gold Nanoparticles via Green Synthesis Using Sargassum crassifolium Extract

2018 ◽  
Vol 765 ◽  
pp. 44-48 ◽  
Author(s):  
Angeline F. Maceda ◽  
Johnny Jim S. Ouano ◽  
Mar Christian O. Que ◽  
Blessie A. Basilia ◽  
Melchor J. Potestas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Ftir Spectroscopy ◽  
Capping Agent ◽  
Visible Spectroscopy ◽  
Spectroscopy Analysis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Uv Visible

This work controls the absorption of gold nanoparticles (GNPs) via green synthesis utilizingSargassumcrassifoliumextract. The amount of seaweed extract acts as both reducing (from Au+to Au0) and capping agent. TheS.crassifoliumextract is mainly composed of biomolecules such as protein and phenolic compounds which are responsible for the synthesis of GNPs. The synthesized GNPs were characterized using UV-Visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and Transmission Electron Microscopy (TEM). UV-Vis spectra revealed peaks around 505 nm to 544 nm which corresponds to the Surface Plasmon Resonance (SPR) of GNPs. FTIR spectroscopy analysis showed peak at 825 cm-1and 1144 cm-1which corresponds to the signature peaks of GNPs. Polydisperse GNPs with varied sizes (between 5 nm to 300 nm) were further confirmed by TEM analysis.

Application of Chiral Ionic Liquid-Modified Gold Nanoparticles in the Chiral Recognition of Amino Acid Enantiomers

2016 ◽  
Vol 70 (10) ◽  
pp. 1649-1654 ◽  
Author(s):  
Lu Huang ◽  
Yi-Ting Chen ◽  
Yan-Xia Li ◽  
Li-Shuang Yu
Keyword(s):  
Gold Nanoparticles ◽  
Amino Acid ◽  
Chiral Recognition ◽  
Visible Spectroscopy ◽  
Recognition Mechanism ◽  
Chiral Ionic Liquids ◽  
Amino Acid Enantiomers ◽  
Transmission Electron ◽  
Chiral Ionic Liquid

Two chiral ionic liquids (ILs), namely 1-ethyl-3-methylimidazole l-tartrate (EMIML-Tar) and 1-ethyl-3-methylimidazole l-lactate (EMIML-Lac), were used to modify gold nanoparticles (AuNPs) for chiral recognition of amino acid enantiomers. Transmission electron microscopy, infrared spectroscopy, ultraviolet-visible spectroscopy, and capillary electrophoresis were used for the characterization of chiral IL-modified AuNPs. Meanwhile, the performance of l-tartaric acid and l-lactic acid as modifiers was investigated to make a comparison. The chiral recognition mechanism is further discussed.

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