Biogenic Synthesis of Gold Nanoparticles from Aspartic Acid - A Preliminary Study

A nanoparticle is an ultra-fine particle with at least one dimension between 1-100 nanometers (nm). Metallic nanoparticles are considered as most promising as they contain remarkable antibacterial properties. Gold nanoparticles are of high importance in research. Aspartic acid is an alpha amino acid and contains one amino group and one carboxylic group. The aim of the current study was to bio synthesize gold nanoparticles using aspartic acid. Gold Chloride (AuCl3) and Aspartic acid (C₄H₇NO₄) were used for the study. AuCL3 solution (0.266 M) was slowly added to 250 aspartic acid with stirring at 45°C. The mixture of the solutions was kept in a long-necked borosilicate flask and continuously stirred on a magnetic stirrer. The formation of gold nanoparticles was confirmed by the change of the colorless solution to a reddish hue. Characterization of the newly formed nanoparticles was then done. After approximately 9 hour incubation and intermittent stirring with a magnetic stirrer the solution color changed from colorless to a reddish hue, which indicated the formation of AuNPs. The spectrometric reading was recorded at a scanning range of 400–700 nm. AuNPs nanoparticles at 24 hours showed an increased intensity and a Surface Plasmon Resonance (SPR) band at 575 nm. The gold nanoparticles by Transmission electron microscopy were confirmed to be spherical in shape and of 20 nm. A simple and efficient method for the synthesis of AuNPs from the aspartic acid was demonstrated. Nano particles were formed in approx. 9 hours with peak absorbance at 24 hours at 575nm. The synthesized nanoparticles were spherical in shape, with an average size of 20 nm. The synthesized nanoparticles showed excellent plasmon resonance and optical properties.

Download Full-text

Sintering and Dielectric Properties of Ba(Mg1/3Ta2/3)O3 Particle Prepared by Spray Pyrolysis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.388.245 ◽

2008 ◽

Vol 388 ◽

pp. 245-248 ◽

Cited By ~ 2

Author(s):

Hiroki Yamada ◽

Takashi Okawa ◽

Takashi Ogihara

Keyword(s):

Electron Microscopy ◽

Spray Pyrolysis ◽

Ultrasonic Spray Pyrolysis ◽

Nano Particles ◽

Ultrasonic Spray ◽

Transmission Electron ◽

Powder Particles ◽

Average Size ◽

Micrometer Size ◽

20 Nm

Ba(Mg1/3Ta2/3)O3 (BMT) powders were successfully prepared by ultrasonic spray pyrolysis from an aqueous solution of Ba, Mg and Ta. The particles characteristics of BMT nano-sized powders were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). As-prepared powder particles had a sub-micrometer size with a narrow distribution. Transmission electron microscopy (TEM) observation revealed that the average size of the BMT nano-particles was around 20 nm, and that these particles were aggregated. The dielectric constant (r) of 23.2 and the Q・f of 98,300 were obtained at 1550°C by a spray pyrolysis.

Download Full-text

Biosynthesis of Silver and Gold Nanoparticles Using Aqueous Extract from Crinum latifolium Leaf and Their Applications Forward Antibacterial Effect and Wastewater Treatment

Journal of Nanomaterials ◽

10.1155/2019/8385935 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 11

Author(s):

Thanh-Truc Vo ◽

Thi Thanh-Ngan Nguyen ◽

Thi Thanh-Tam Huynh ◽

Thi Thuy-Trang Vo ◽

Thi Thuy-Nhung Nguyen ◽

...

Keyword(s):

Gold Nanoparticles ◽

Aqueous Extract ◽

Metallic Nanoparticles ◽

Antibacterial Effect ◽

Average Diameter ◽

Catalytic Performance ◽

Biologically Active ◽

Bacterial Strains ◽

Uv Visible ◽

Average Size

Crinum latifolium (CL) leaf is a source of various biologically active compounds such as alkaloid and phenolic compounds, which exhibit anti-inflammatory, antitumor, and antimicrobial effects. In the purpose of expanding applications for the field of bionanotechnology, we report biosynthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) by using aqueous extract from C. latifolium leaf and explore antibacterial activity and catalytic performance for degradation of pollutants. The formation of CL-AgNPs and CL-AuNPs is confirmed and optimized by UV-visible spectroscopy with surface plasmon resonance (SPR) peaks at around 402 and 539 nm, respectively. The spherical CL-AgNPs have an average diameter of 20.5 nm and the multishaped CL-AuNPs possess an average size of 17.6 nm. The actions of four bacterial strains were strongly inhibited by using the CL-AgNPs. Furthermore, the biosynthesized metallic nanoparticles (MNPs) exhibited the excellent catalytic degradation performance of pollutants.

Download Full-text

Morphological and Optical Characterization of Gold Nanoparticles Decorated Porous Silicon

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2019.16094 ◽

2019 ◽

Vol 19 (6) ◽

pp. 3604-3609

Author(s):

F Severiano ◽

V. L Gayou ◽

G García ◽

J. A Luna-López ◽

H. Martínez Gutiérrez ◽

...

Keyword(s):

Gold Nanoparticles ◽

Porous Silicon ◽

Chemical Etching ◽

Silicon Layer ◽

Porous Silicon Layer ◽

Sem Analysis ◽

Etching Time ◽

Si Nanocrystals ◽

Average Size ◽

20 Nm

In this article, physical characteristics of porous silicon (PS) obtained by electro chemical etching using HAuCl4 in the electrolyte are described. The morphological and optical features of PS decorated with gold-nanoparticles (AuNPs) were analyzed in function of the chemical etching time. The insertion of AuNPs inside the PS were performed simultaneously with the formation of the porous silicon layer. Scanning electron microscopy (SEM) analysis showed the formation and incorporation of AuNPs with an average size of 20 nm in the PS structure, which has a pore size of 1.5 μm. Also, it was possible to observe the loss of Si in function of the etching time. Photoluminescence spectroscopy analysis shows a decreasing of the PL intensity, which can be related to the presence of oxygen in the samples. Raman spectroscopy was used to estimate the size of the Si nanocrystals in the PS structure, which suffers a reduction in size due to the presence of HAuCl4 in the electrolyte.

Download Full-text

Synthesis of Urethane Base Composite Materials with Metallic Nanoparticles

MRS Proceedings ◽

10.1557/opl.2013.854 ◽

2013 ◽

Vol 1547 ◽

pp. 141-147 ◽

Cited By ~ 1

Author(s):

Anayansi Estrada Monje ◽

J. Roberto Herrera Reséndiz

Keyword(s):

Silver Nanoparticles ◽

Surface Morphology ◽

Metallic Nanoparticles ◽

Antimicrobial Properties ◽

Polyurethane Foams ◽

Polymer Materials ◽

Antifungal Properties ◽

Base Composite ◽

Average Size ◽

20 Nm

ABSTRACTThe antimicrobial properties of polymer materials are used in a verity of applications. Silver nanoparticles are commonly applied to polyurethane foams to obtain antifungal properties. For this study a series of nanocomposites (PU–Ag) from a urethane-type polymer (PU) were reinforced with various amounts of silver nanoparticles having an average size of 20 nm. The surface morphology and antifungal capacity of the nanocomposites were evaluated. As a result, a different surface morphology from PU was found in PU–Ag nanocomposites. The latter nanocomposite showed enhanced thermal and mechanical properties, when compared with the PU without silver nanoaprticles. The nanocomposite also exhibited good antifungal properties that can be used in a variety of applications.

Download Full-text

Fullerene C60 Films Cross-Linked with Octane-1,8-Dithiol: Preparation, Characterization and the Use as Template for Chemical Deposition of Gold Nanoparticles

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.205 ◽

2008 ◽

Vol 8 (8) ◽

pp. 3828-3837 ◽

Cited By ~ 6

Author(s):

Víctor Meza-Laguna ◽

Elena V. Basiuk ◽

Edgar Alvarez-Zauco ◽

Taras Yu. Gromovoy ◽

Oscar Amelines-Sarria ◽

...

Keyword(s):

Gold Nanoparticles ◽

Density Functional ◽

Chemical Deposition ◽

Density Functional Theory Calculations ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Covalent Bonds ◽

Transmission Electron ◽

Average Size ◽

20 Nm

We report on the preparation of fullerene C60 thin films chemically cross-linked with octane-1,8-dithiol, which are capable of binding gold nanoparticles. The formation of a polymer was directly proved by means of laser desorption/ionization time-of-flight mass spectra, in which we observed the cleavage of fullerene–dithiol polymer at different bonds. Fourier-transform infrared, Raman and UV-visible spectra of the functionalized films exhibited notorious changes due to the formation of new covalent bonds between C60 molecules and bifunctional thiol. We further demonstrated that the dithiol-functionalized fullerene can be employed as a support for stable and homogeneous deposition of gold nanoparticles. Their average size is about 5 nm according to high-resolution transmission electron microscopy observations, and up to 20 nm, as found from scanning tunneling microscopy images. The proposed binding mechanism is through a strong coordination attachment between Au nanoclusters and sulfur donor atoms of the functionalized fullerene, as supported by density functional theory calculations.

Download Full-text

The Surface Plasmon Scattering Patterns of Gold Nanoparticles and Agglomerates

Heat Transfer, Part B ◽

10.1115/imece2005-82927 ◽

2005 ◽

Author(s):

Pradeep Garudadri Venkata ◽

Mustafa M. Aslan ◽

M. Pinar Mengu¨c ◽

Gorden Videen

Keyword(s):

Gold Nanoparticles ◽

Surface Plasmon ◽

Self Assembly ◽

Metallic Nanoparticles ◽

Glass Production ◽

Visible Spectrum ◽

Nano Particles ◽

Colored Glass ◽

Significant Information ◽

Scattering Matrix Elements

Metallic nanoparticles display considerably different optical properties than those of their bulk counterparts. They have long been of interest in several novel applications, from colored glass production of medieval times to molecular-level sensors of today. Recently, there has been significant interest in characterization of such small particles via surface plasmons, for example for monitoring of the actual self-assembly purposes. For such characterization, we need scattering patterns by different type of particles and agglomerates on or near the surface. Here we present a methodology to predict the required scattering patterns of single particles and agglomerates on or near a surface subjected to surface plasmon waves. We investigate the effect of size, shape and orientation of gold nano particles on their scattering patterns both in the visible spectrum and at resonance wavelengths. The results show that the normalized scattering matrix elements (Mij) at certain observation angles and incident wavelengths provide significant information to monitor self-assembly process of gold nanoparticles on a gold substrate.

Download Full-text

Biogenic Gold Nanoparticles Decrease Methylene Blue Photobleaching and Enhance Antimicrobial Photodynamic Therapy

Molecules ◽

10.3390/molecules26030623 ◽

2021 ◽

Vol 26 (3) ◽

pp. 623

Author(s):

Irena Maliszewska ◽

Ewelina Wanarska ◽

Alex C. Thompson ◽

Ifor D. W. Samuel ◽

Katarzyna Matczyszyn

Keyword(s):

Methylene Blue ◽

Gold Nanoparticles ◽

Photodynamic Therapy ◽

Bactericidal Effect ◽

Antimicrobial Photodynamic Therapy ◽

Plasmon Band ◽

Escherichia Coli Bacteria ◽

Average Size ◽

20 Nm ◽

Nanoparticle Sizes

Antibiotic resistance is a growing concern that is driving the exploration of alternative ways of killing bacteria. Here we show that gold nanoparticles synthesized by the mycelium of Mucor plumbeus are an effective medium for antimicrobial photodynamic therapy (PDT). These particles are spherical in shape, uniformly distributed without any significant agglomeration, and show a single plasmon band at 522–523 nm. The nanoparticle sizes range from 13 to 25 nm, and possess an average size of 17 ± 4 nm. In PDT, light (from a source consisting of nine LEDs with a peak wavelength of 640 nm and FWMH 20 nm arranged in a 3 × 3 array), a photosensitiser (methylene blue), and oxygen are used to kill undesired cells. We show that the biogenic nanoparticles enhance the effectiveness of the photosensitiser, methylene blue, and so can be used to kill both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The enhanced effectiveness means that we could kill these bacteria with a simple, small LED-based light source. We show that the biogenic gold nanoparticles prevent fast photobleaching, thereby enhancing the photoactivity of the methylene blue (MB) molecules and their bactericidal effect.

Download Full-text

Flexural Modulus and Strength of Cold Cured Poly(methylmethacrylate) Reinforced with TiO2 Nano Particles

Materiale Plastice ◽

10.37358/mp.20.4.5402 ◽

2021 ◽

Vol 57 (4) ◽

pp. 13-20

Author(s):

Sebastian Balos ◽

Branislava Petronijevic Sarcev ◽

Ivan Sarcev ◽

Petar Janjatovic ◽

Branka Pilic ◽

...

Keyword(s):

Flexural Strength ◽

Flexural Modulus ◽

Antibacterial Properties ◽

Polymer Chains ◽

Nano Particles ◽

Dsc Analysis ◽

Tio2 Addition ◽

20 Nm ◽

Reduced Mobility ◽

Pmma Resin

The most significant disadvantage of cold cured poly (methyl methacrylate) - PMMA is its poor mechanical properties, mainly in flexure. The aim of this work is to explore the modulus and flexural strength of modified cold cured PMMA modified with low TiO2 addition, which can also have antibacterial properties. Commercial cold cured PMMA resin, consisting of powder and liquid components, were modified by adding 0.05 %, 0.2 %, and 1.5 wt. % 20 nm hydrophobic TiO2. The specimen s flexural modulus and strength were tested, while heat properties were determined with DSC analysis. SEM and EDX were used to study fracture surfaces of tested specimens. In all modified specimens, an increased flexural modulus and flexural strength were recorded. In all specimens, the appearance of agglomerates was noted. Glass transition temperatures also increased, as the result of the appearance of polymer chains with reduced mobility around nanoparticles. 0.2 % of 20 nm TiO2 nanoparticle content proved to be the most efficient in increasing flexural modulus and strength.

Download Full-text

Green and Synthetic Metallic Nanoparticles - Obtaining, Characterization and Biological Evaluation in Association with Lupeol

Revista de Chimie ◽

10.37358/rc.20.5.8137 ◽

2020 ◽

Vol 71 (5) ◽

pp. 299-304

Author(s):

Flavia Bociort ◽

Adelina Cheveresan ◽

Razvan Dragoi ◽

Alina Heghes ◽

Camelia Szuhanek ◽

...

Keyword(s):

Colon Cancer ◽

Gold Nanoparticles ◽

Cancer Cells ◽

Metallic Nanoparticles ◽

Chemical Characterization ◽

Biological Evaluation ◽

Colon Cancer Cells ◽

Lemon Balm ◽

Physico Chemical ◽

Average Size

The field of metal nanotechnology continues to draw the attention of researchers from different areas due to the outstanding properties of nanoparticles. The main aims of this research were to obtain and to study two types of gold nanoparticles; different obtaining pathways (the chemical synthesis and the biosynthesis based on an aqueous extract of lemon balm) were involved in this research. The chemically synthesized nanoparticles were loaded with lupeol. After a preliminary physico-chemical characterization, the compounds obtained were tested in order to evaluate the effects on the viability of colon cancer cells. The formulation of these new gold nanoparticles with average size between 38 and 82 nm, with a good stability against the tendency to form agglomerations according to the Zeta potential values, was confirmed by UV-Vis spectra; the particles containing lupeol have show the best activity against the colon cancer cells.

Download Full-text

Fabrication of Nano-Sized Tin Oxide Powder by Spray Pyrolysis Process

MRS Proceedings ◽

10.1557/proc-1174-v09-31 ◽

2009 ◽

Vol 1174 ◽

Cited By ~ 1

Author(s):

Jaekeun Yu ◽

Jwayeon Kim ◽

Jeoungsu Han

Keyword(s):

Particle Size ◽

Spray Pyrolysis ◽

Reaction Temperature ◽

Tin Oxide ◽

Average Particle Size ◽

Raw Material ◽

Nano Particles ◽

Average Particle ◽

Average Size ◽

20 Nm

AbstractBy using tin chloride solution as the raw material, a nano-sized tin oxide powder with average particle size below 50 nm is generated by spray pyrolysis reaction. This study also examines the influences of the reaction parameters such as reaction temperature and the concentration of raw material solution on the powder properties. As the reaction temperature increases from 800 to 850 ℃, the average particle size of the generated powder increases from 20 nm to 30 nm. As the reaction temperature reaches 900 ℃, the droplets are composed of nano-particles with average size of 30 nm, while the average size of individual particles increases remarkably up to 80˜100 nm. When the tin concentration reaches 75 g/L, the average particle size of the powder is below 20 nm. When the tin concentration reaches 150 g/L, the droplets are composed of nano particles with average size around 30 nm, whereas the average size of independent particles increases up to 80˜100 nm. When the concentration reaches 400 g/L, the droplets are composed of nano-particles with average size of 30 nm.

Download Full-text