Method For Synthesis Of Gold Nanoparticles Research Articles

Eco-Friendly Synthesis Methods of Gold Nanoparticles, Their Characterization and Applications in Diagnostic, Therapeutic and Sensors

Nanoparticles have unique traits which make them useful for different purposes. Numerous methods are used to manufacture nanoparticles at commercial scale. Gold nanoparticles (AuNPs) are one of the most utilized and preferred nanoparticles due to their traits like low resistivity, less toxicity, optical, high stability, fluorescence quenching ability, and "surface plasmon resonance". Gold nanoparticles were utilized in ancient Roman Times for staining glasses and till now their new applications are being discovered every day. Various methodologies are utilized for Gold nanoparticle synthesis including conventional chemical methods, UV rays, polymers, ultrasound, plant and microbe-mediated techniques, etc. Conventional techniques are not eco-friendly or cost-effective. Nowadays plants and microbes being cost-effective and eco-friendly are preferred for gold nanoparticle synthesis. Various extracellular, intracellular, and biomolecular techniques are being utilized to manufacture gold nanoparticles. Gold nanoparticles have a vast scope in chemical, biomedicine, food, electronic and forensic industries. AuNPs are widely utilized as sensors, also as carriers in Drug delivery, Photothermal therapy, Heavy metal ion detection etc. This review describes various synthesis techniques, applications, and characterizations of AuNPs.

Antibacterial and photocatalytic activity of visible-light-induced synthesized gold nanoparticles by using Lantana camara flower extract

Abstract A facile synthesis method of gold nanoparticles (AuNPs) utilizing Lantana camara flower extract (LFE) using visible light illumination towards the bio-reduction system has been conducted. The systematic characterizations of AuNPs were employed using transmission electron microscopy, X-ray powder diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The nanoparticles having a particle size of ranging 4.8–25 nm were obtained with dependence on the LFE concentration of the extract and time of light irradiation. The antibacterial activity of AuNPs was evaluated against Escherichia coli, Staphylococcus aureus, Propionibacterium acnes, and Pseudomonas aeruginosa, and the photocatalytic activity was examined in methylene blue photooxidation. The overall results point to a promising photochemical synthesis of AuNPs utilizing plant extract and the potential activities of synthesized nanoparticles as antibacterial agents and photocatalysts.

AuNPs and graphdiyne nanocomposite as robust electrocatalyst for methyl parathion detection in real samples.

The present work describes a simple and rapid synthesis method of gold nanoparticles and graphdiyne (AuNPs@GDY) nanocomposites including porous structure. Moreover, the synthesized AuNPs@GDY material was decorated on the glassy carbon electrode (GCE) with a drop coating method to construct a non-enzymatic electrochemical pesticides sensor. The micro-morphology and elemental composition of the materials were characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The electrocatalysis and conductivity of the material were studied with cyclic voltammetry (CV) and impedance method, respectively. The properties of the sensor were investigated by CV and differential pulse voltammetry (DPV). The results showed that AuNPs@GDY exhibited excellent electrocatalytic ability for methyl parathion in a wide linear range (from 0.25ng/mL to 24.43μg/mL) and low limit of detection value (6.2pg/mL). Furthermore, the DPV method used in this paper was accurate and sensitive, and could be used for routine quality control of methyl parathion in kiwi fruit and tomato samples.

Eco-Friendly Methods of Gold Nanoparticles Synthesis

Background:Owing to the importance of metallic nanoparticles, different researches and studies have been induced to synthesize them in many ways. One of the ways that paid attention last years is the green synthesis methods of nanoparticles or the so-called ''eco-friendly methods''. The most common sources that has been used for green synthesis of nanoparticles are plants, leaves, fungi and microorganisms. The green synthesis methods are widely used because they are inexpensive, usable, and nontoxic. Moreover, plant extracts are rich in reducing and capping agents.Methods:In the present review, green synthesis methods of gold nanoparticles (AuNps) using Chitosan, Klebsiella pneumoniae, Magnolia Kobus, Elettaria cardamomum (Elaichi) aqueous extract and other agents as a reducing/capping agents will be discussed in details. Moreover, we will make a comparison between different green routes of synthesis and the characterization of the obtained nanoparticles from each route.Results:The characterization and applications of the prepared GNPs from different routes are reviewed.Conclusion:The utilization of gold nanoparticles has been advocated because of their high biocomptability, administration in clinical applicability and in diverse aspects of life. It seems that plants are good candidates for nanoparticles production because they are inexpensive, available and renewable sources in addition, it is too simple to prepare extracts from them. Moreover, the great diversity in the types and amounts of reducing agents from plant extracts is responsible for the effortless generation of metallic nanoparticles of various shapes and morphologies.

One-pot facile synthesis of silk sericin-capped gold nanoparticles by UVC radiation: Investigation of stability, biocompatibility, and antibacterial activity.

Herein, an easy one-pot synthesis method for gold nanoparticles (AuNPs), involving only gold salt and sericin extracted from silkworm cocoon in the presence of ultraviolet C (UVC) radiation, was developed. Nanoparticle formation was confirmed by characteristic surface plasmon resonance peaks at 520-540 nm wavelengths, and the influence of silk sericin on enhancing the colloidal stability of AuNPs was confirmed. Transmission electron microscopy examination showed the average size (<10 nm) and size distribution decreased significantly with higher sericin concentration. No antibacterial activity was observed on Gram-positive Bacillus subtilis or Gram-negative Escherichia coli for sole AuNPs (0.065-0.26 mg/ml), but the conjugation of AuNPs with streptomycin antibiotic decreased significantly the required minimum inhibitory concentration doses, as also confirmed with agar plating, Scanning Electron Microscopy and Atomic Force Microscopy analyses. Furthermore, sericin-capped AuNPs showed high cell viabilities (>100%) and no sign of any detectable apoptosis or necrosis in 1-day incubation. Also, high real-time cell proliferation results of AuNPs competitive with positive control groups implied excellent in vitro biocompatibility. These results evidenced that sericin enhanced the colloidal stability of AuNPs and the biological activities of sericin-capped AuNPs reported here could render them suitable nanoscale vehicles for biomedical applications.

Tailored porphyrin–gold nanoparticles for biomedical applications

In this review we present an updated survey of the main synthesis methods of gold nanoparticles (AuNPs) in order to obtain various tailored nanosystems for biomedical imaging. The synthesis approach significantly impacts on the AuNPs properties such as surface chemistry, biocompatibility and cytotoxicity. In recent years, nanomedicine emphasized the development of functionalized AuNPs for biomedical imaging. AuNPs are a good option for used as delivery photosensitizer agents for PDT of cancer. For example, the complex formed from AuNPs functionalized with PEGylate porphyrins presents several advantages in the medical field such as a better use in photodynamic therapy because of high triplet states and singlet oxygen quantum yield efficiency of porphyrin molecules.

A review of the biological synthesis of gold nanoparticles using fruit extracts: scientific potential and application

Gold nanoparticles (GNPs) are well-known nanomaterials that can be used for multiple biomedical applications. There are various methods for synthesis of GNPs using microorganisms and plants, particularly through the use of fruit extracts. Their use is due to the fact that fruit extracts are the natural concentrate of substances that possesses therapeutic properties. In this review, we aim to compare the recent studies concerning the methods for synthesis of GNPs from fruit extracts, the methods used to characterize the properties of GNPs and capping biomaterial and the potential applications of GNPs. The most frequently used methods to characterize GNPs and capping biomaterial are UV–visible spectroscopy, transmission or scanning electron microscopy, dynamic light scattering and Fourier transformation infrared spectroscopy techniques. Because of GNPs’ optoelectronic properties, biocompatibility, stability and oxidation resistance, they can be used in areas such as electronics, chemical and biological sensing, tumour imaging, drug delivery and phototherapy.

Controlling the Absorption Spectra of Gold Nanoparticles Synthesized via Green Synthesis Using Brown Seaweed (&lt;i&gt;Sargassum&lt;/i&gt; &lt;i&gt;crassifolium) &lt;/i&gt;Extract

Gold nanoparticles were synthesized using brown seaweed (Sargassum crassifolium) extract and chloroauric acid solution. This is an easy, cheap and environment friendly synthesis method for the formation of gold nanoparticles. The gold nanoparticles with varying amount of seaweed extract was characterized using Ultraviolet-visible spectroscopy. Moreover, Transmission Electron Microscopy characterization was used to observe the shape and size of gold nanoparticles. Experimental results revealed that varying the amount of brown seaweed extract can control the optical absorption spectra of the produced gold nanoparticles. Greater amount of brown seaweed extract will exhibit peak in the lower wavelength while smaller amount of seaweed extract will exhibit peak in the higher wavelength. It is believed that the wavelength of free surface electrons resonance is related to the shift of absorption peak. TEM images revealed a more spherical and smaller particles as the amount of brown seaweed extract was increased. This simple green synthesis method of gold nanoparticles will give a cost effective route in the mass production of gold nanoparticles for biomedical applications.

Biosynthesis of Gold Nanoparticles by Flavonoids from Lilium casa blanca

Biosynthesis of gold nanoparticles (GNPs) by flavonoids from Lilium casa blanca has been developed. Several parameters such as pH, reaction temperature, reaction time and concentration of flavonoids were explored to control the formation of the GNPs. The synthesized GNPs were characterized by UV–Vis spectroscopy, transmission electron microscopy and X-ray diffraction. Stability and catalytic activity of the synthesized GNPs were also discussed. The results showed that the synthesized GNPs were in spherical, about 2.6 nm, with a face centered cubic structure. Synthesized GNPs showed good catalytic activity in the reduction of p-nitrophenol (p-NP) to p-aminphenol (p-AP). This method for synthesis of GNPs is simple, economic, nontoxic and efficient.

Synthesis methods of gold nanoparticles for Localized Surface Plasmon Resonance (LSPR) sensor applications

Gold nanoparticles (GNPs) have been known as an excellent characteristic for Local Surface Plasmon Resonance (LSPR) sensors due to their sensitive spectral response to the local environment of the nanoparticle surface and ease of monitoring the light signal due to their strong scattering or absorption. Prior the technologies, GNPs based LSPR has been commercialized and have become a central tool for characterizing and quantifying in various field. In this review, we presented a brief introduction on the history of surface plasmon, the theory behind the surface plasmon resonance (SPR) and the principles of LSPR. We also reported on the synthetization as well of the properties of the GNPs and the applications in current LSPR sensors.

Green synthesis of gold nanoparticles using chlorogenic acid and their enhanced performance for inflammation

Here we developed a novel green synthesis method for gold nanoparticles (CGA-AuNPs) using chlorogenic acid (CGA) as reductants without the use of other chemicals and validated the anti-inflammatory efficacy of CGA-AuNPs in vitro and in vivo. The resulting CGA-AuNPs appeared predominantly spherical in shape with an average diameter of 22.25±4.78nm. The crystalline nature of the CGA-AuNPs was confirmed by high-resolution X-ray diffraction and by selected-area electron diffraction analyses. High-resolution liquid chromatography/electrospray ionization mass spectrometry revealed that the caffeic acid moiety of CGA forms quinone structure through a two-electron oxidation causing the reduction of Au3+ to Au0. When compared to CGA, CGA-AuNPs exhibited enhanced anti-inflammatory effects on NF-κB-mediated inflammatory network, as well as cell adhesion. Collectively, green synthesis of CGA-AuNPs using bioactive reductants and mechanistic studies based on mass spectrometry may open up new directions in nanomedicine and CGA-AuNPs can be an anti-inflammatory nanomedicine for future applications. From the Clinical EditorGold nanoparticles (Au NPs) have been shown to be very useful in many applications due to their easy functionalization capability. In this article, the authors demonstrated a novel method for the synthesis of gold nanoparticles using chlorogenic acid (CGA) as reductants. In-vitro experiments also confirmed biological activity of the resultant gold nanoparticles. Further in-vivo studies are awaited.

One-step synthesis of highly-biocompatible spherical gold nanoparticles using Artocarpus heterophyllus Lam. (jackfruit) fruit extract and its effect on pathogens.

Novel approaches for the synthesis of gold nanoparticles (AuNPs) are of great importance due to its vast spectrum of applications in diverse fields, including medical diagnostics and therapeutics. Te presented study reports the successful AuNPs' synthesis using Artocarpus heterophyllus Lam. extract, and provides detailed characterization and evaluation of its antibacterial potential. The aim was to develop a cost-effective and environmentally friendly synthesis method of gold nanoparticles using aqueous fruit extract of Artocarpus heterophyllus Lam. as a reducing and capping agent, which has proven activity against human pathogens, such as microbial species E.coli and Streptobacillus sps. Characterizations were carried out using ultraviolet-visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray and Fourier-Transform infra-red spectroscopy (FT-IR). SEM images showed the formation of gold nanoparticles with an average size of 20-25 nm. Spectra collected while infra-red analysis contained broad peaks in ranges from 4000-400 cm -1 . It can be concluded that the fruit of Artocarpus heterophyllus Lam. can be good source for synthesis of gold nanoparticles which showed antimicrobial activity against investigated microbes, in particul E. coli, and Streptobacillus. An important outcome of this study will be the development of value-added products from the medicinal plant Artocarpus heterophyllus Lam. for the biomedical and nanotechnology-based industries.

Green synthesis of gold nanoparticles with willow tree bark extract: a sensitive colourimetric sensor for cysteine detection

In this work we report an easy and simple green synthesis method for gold nanoparticles (GNPs) using willow tree bark extract.

Facile synthesis of concentrated gold nanoparticles with low size-distribution in water: temperature and pH controls

The citrate reduction method for the synthesis of gold nanoparticles (GNPs) has known advantages but usually provides the products with low nanoparticle concentration and limits its application. Herein, we report a facile method to synthesize GNPs from concentrated chloroauric acid (2.5 mM) via adding sodium hydroxide and controlling the temperature. It was found that adding a proper amount of sodium hydroxide can produce uniform concentrated GNPs with low size distribution; otherwise, the largely distributed nanoparticles or instable colloids were obtained. The low reaction temperature is helpful to control the nanoparticle formation rate, and uniform GNPs can be obtained in presence of optimized NaOH concentrations. The pH values of the obtained uniform GNPs were found to be very near to neutral, and the pH influence on the particle size distribution may reveal the different formation mechanism of GNPs at high or low pH condition. Moreover, this modified synthesis method can save more than 90% energy in the heating step. Such environmental-friendly synthesis method for gold nanoparticles may have a great potential in large-scale manufacturing for commercial and industrial demand.

Facile controlled preparation of gold nanoparticles with amphiphilic thiacalix[4]arene as reductant and stabilizer

A facile controlled synthesis method of gold nanoparticles (AuNPs) under mild conditions has been developed by combining the stabilization ability of amphiphilic thiacalixarene and the reduction ability of phenolic moieties together, and the particle sizes of AuNPs can be readily controlled by only adjusting the feeding ratio of Au/S.

Au Nanoparticles as SERS Probes of the Silica Surface Layer Structure in the Absence and Presence of Adsorbates

A simple synthesis method of gold nanoparticles dispersed at the silica surface which allows a progressive and controlled increase of Au particle population is described. An important step of the preparation is treatment in H2 at 573 K, which allows cleaning the surface of Au from chlorine, a frequently present impurity which can interfere with the Au/silica interaction. At the lowest concentration, the Au particles (almost spherical, d ≅ 4 nm) are isolated, while at the highest loading clusters of particles are becoming more frequent. The increase of the surface Au particle concentration is accompanied by a gradual change of the absorption spectrum in the visible−NIR, with progressive appearance of an intense tail in the NIR region. This tail is ascribed to the formation of a growing amount of particle aggregates. This assignment is fully confirmed by an HRTEM study, which clearly shows the presence of aggregates at the highest loading. The Raman spectra obtained by irradiation with a laser at 785 nm, i....