Synthesis of gold nanotriangles and silver nanoparticles using aloevera plant extract (original) (raw)
Related papers
Green Synthesis of Gold Nanoparticles Using (ALOE VERA) Aqueous Extract
2014
2 Abstract: In the present study we explore the reducing and capping potential of aqueous extract from Aloe vera for the synthesis of gold nanoparticles. The extract with different concentration reduced with HAuCl aqueous 4 solution at room temperature. The color change, pH change and UV-visible spectroscopic analysis reveal the Surface Plasmon Resonance (SPR) of the final reaction product which confirms the reduction of Au ion to gold 3+ nanoparticles. XRD, particle size analysis results represent strong reducing potential of Aloe vera aqueous extract which can also be tested in the green synthesis of other metallic nanoparticles.
Journal of Nanomaterials & Molecular Nanotechnology, 2016
This work, conducted biological synthesis and characterization of gold nanoparticles (AuNPs) through environmentally friendly technology using plant extracts: cactus (Opuntia sp.), onion (Allum sp.), pear (Pyrus sp.), coffee (Coffea sp.) and laurel (Laurus sp.), as a reducing agent and stabilizers. The methodology consists in merging Turkevich et al., 1951 and Rico-Moctezuma et al., 2010 techniques. The characterization with UV-Visible spectrophotometry determined maximum absorbance at 527-537 nm, corresponding with previously reported AuNPs absorbance, while transmission electron microscopy (TEM) and Atomic Force Microscopy (AFM) confirmed that the gold nanoparticles biosynthesis produced different shapes, including spheres, cubes, cones, cylinders and others with a size of 5-100 nm depending on the extract used, so that the proposed method is useful, eco-friendly, quick and inexpensive to synthesize AuNPs. Furthermore these AuNPs can be functionalized.
GREEN SYNTHESIS AND CHARACTERIZATION OF GOLD AND SILVER NANOPARTICLES
Gold nanoparticles (GNPs) and silver nanoparticles (SNPs) are very attractive materials for nanotechnology, nanobiology and nanomedicine. We employ β-cyclodextrin (βCD) both as reducing and stabilizing agent for the preparation of GNPs and SNPs aqueous dispersions, to be used in biological applications. HAuCl 4 and respectively AgNO 3 were reduced with βCD in alkaline medium at room temperature. Reactions were monitored by measuring the intensity of the characteristic surface plasmon resonance (SPR) absorption band at 520 nm for GNPs, and at 404 nm for SNPs. The size of particles was determined from TEM images. Particularly, the average diameter of GNPs is 7.6 nm and for SNPs is 13.1 nm. The dispersions remained stable for at least a year after preparation. The nanoparticles were further characterized by AFM imaging, zeta potential and dynamic light scattering measurements, as well as by FT-Raman spectra. Their stability against acid (HCl) and saline (NaCl) solutions was also investigated.
Biological synthesis of triangular gold nanoprisms
Nature Materials, 2004
The optoelectronic and physicochemical properties of nanoscale matter are a strong function of particle size. Nanoparticle shape also contributes significantly to modulating their electronic properties. Several shapes ranging from rods to wires to plates to teardrop structures may be obtained by chemical methods; triangular nanoparticles have been synthesized by using a seeded growth process. Here, we report the discovery that the extract from the lemongrass plant, when reacted with aqueous chloroaurate ions, yields a high percentage of thin, flat, single-crystalline gold nanotriangles. The nanotriangles seem to grow by a process involving rapid reduction, assembly and room-temperature sintering of 'liquid-like' spherical gold nanoparticles. The anisotropy in nanoparticle shape results in large near-infrared absorption by the particles, and highly anisotropic electron transport in films of the nanotriangles.
In the present study, an environmental friendly synthesis of silver nanoparticles (AgNPs) has been investigated using Aloe Vera plant leaves extract act as reducing and stabilizing agent. The formation of AgNPs was confirmed by changing their color to dark brown due to surface plasmon resonance (SPR) phenomenon. The effect of process parameters on synthesis of AgNPs from Aloe Vera leaves extract such as AgNO 3 concentration (molarity), extract volume percent, sunlight exposure time and temperature were studied. The AgNPs obtained were characterized using UV-vis spectroscopy, Atomic Absorption Spectroscopy (AAS), Atomic force microscopy (AFM), and Fourier Transformation Infrared Spectroscopy (FTIR). UV-Vis spectroscopy showed the SPR peaks for AgNPs using Aloe Vera leaves extract were between 420-490 nm. Atomic force microscopy (AFM) showed the AgNPs are spherical in shapes with the average particle diameters between 34-102 nm. The best conditions for synthesis of AgNPs using Aloe Vera leaves extract were found at 5 mM AgNO 3 concentration, 15% extract volume percent, for 10 min of sunlight exposure and temperature at 60 o C.