Activity Of Gold Nanoparticles Research Articles

A Recent Review on Synthesis, Characterization and Activities of Gold Nanoparticles Using Plant Extracts

Abstract: Despite advances in synthetic medications, medicinal herbs have empowered mankind with a wide range of efficacious medicines to lessen or eliminate illnesses and suffering from diseases. Since the last decade there has been increasing enthusiasm for the synthesis of gold nanoparticles particularly from herbal extract because the method is a one pot process, environment friendly, safe, convenient and can be produced in large scale. Aqueous extract of several parts of herbs have been utilised, like flower, fruit peel, fruit juice, leaf, stem, seed, rhizome for synthesizing gold nanoparticles. Plants contain phytoconstituents such as alkaloids, flavonoids, polysaccharides, phenols, terpenoids and proteins. These secondary metabolites present, serve as capping and reducing agents in plants, increasing the rate of nanoparticle reduction and stabilisation. Change in colour of yellow coloured auric chloride solution used in the synthesis to ruby red or deep purple or magenta confirms the formation of gold nanoparticles. Various techniques such as UV-visible spectroscopy, scanning electron microscopy, fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering, powder X-ray diffraction, energy dispersive spectroscopy and zeta potential are used to characterize nanoparticles of various sizes, shapes, and surface areas. This review's goal is to present an overview of recent developments in herbal extract-assisted gold nanoparticle synthesis, characterization and applications. Keywords: Plant extract, Gold nanoparticles, Synthesis, Characterization, Activity.

Synthesis of metal-2D metal-organic framework composite Nanosheets and Their Application in Cascade Catalytic Reactions

Cascade reactions have always had an irreplaceable position in biocatalysis. In this work, we are inspired by the cascade reactions catalyzed by natural enzymes and combining the peroxidase mimetic activity of metal organic frameworks (MOF) nanosheets and the glucose oxidation mimetic enzyme activity of gold nanoparticles (AuNPs) constitutes a dual nanozyme mimetic cascade reaction. AuNPs/Zn-TCPP nanosheets with dual mimetic enzyme activities were prepared by in situ reduction to generate AuNPs on the surface of 2D MOF. And used to further detect the content of hydrogen peroxide or glucose.

Antibacterial Effect of Gold Nanoparticles Coated Dental Floss against Cariogenic Bacteria

Background: Carious lesions can occur on the proximal surfaces of the posterior teeth. Streptococcus mutans and Streptococcus sobrinus, are the main acidogenic bacteria that are commonly associated to dental caries. Interproximal cleaning is an important form of oral self-care habits, considering such areas of the dentition are easily affected by caries. Accordingly, dental floss has been used as an additional tool to enhance the quality of the cleaning process. It is reasonable that dental flossing should reduce interproximal caries risk because it is capable of removing parts of the interproximal plaque. The aim of this study was to evaluate the antibacterial activity of gold nanoparticle (AuNPs), when coated on unwaxed dental floss.Methods: Streptococcus mutans and Streptococcus sobrinus were cultured in Brain Heart Infusion (BHI) agar. Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the AuNPs with subcultures so obtained. Then, the bacteria were grown and spread on blood agar on which identical lengths (20mm) of unwaxed dental floss coated with gold nanoparticles (AuNPs) at concentration of 0.05, 0.1, and 0.5 mg/mL were placed. Control included untreated unwaxed dental floss and unwaxed dental floss with 0.2% Chlorhexidine (CHX). Five randomized sites of the inhibition zones were measured in millimeters in each concentration per floss. Means ± S.D. of the inhibition zones were calculated.Results: The MIC and MBC of AuNPs against S. sobrinus and S. mutans were 0.5 μg/mL and 1.0 μg/mL, respectively. The results indicated that gold nanoparticles (AuNPs) coated unwaxed dental floss, placed on blood agar with S. mutans and S. sobrinus demonstrated significant inhibition of bacterial growth. Gold nanoparticles (AuNPs) coated unwaxed dental floss at 0.05, 0.1, 0.5 mg/mL resulted in zones of inhibition ranging from 2.93 ± 0.30 mm to 4.71 ± 0.32 mm for S. sobrinus and 2.95 ± 1.73 mm to 5.18 ± 0.61 mm for S. mutans, respectively.Conclusion: Invitro study demonstrated that the AuNPs-coated unwaxed dental floss had antibacterial activities against cariogenic bacteria.

THE SYNERGISTIC EFFECT OF GOLD NANOPARTICLE LOADED WITH CEFTAZIDIUM ANTIBIOTIC AGAINST MULTIDRUG ERSISTANCE PSEUDOMONAS AERUGINOSA

This study was aimed to evaluate the antimicrobial activity of gold nanoparticles that was synthesized by biological method using Aloe Vera extract. The Surface morphology of the synthesized gold nanoparticles was confirmed by Atomic force microscope (AFM) while the nature of functional groups present in gold nanoparticles was determined by FT-IR analysis. The antibacterial activity of gold nanoparticle was tested against multidrug resistance (MDR)pseudomonas aeruginosa, the results showed a significant effect against MDR isolates. Gold nanoparticle was loaded with ceftazidium antibiotic in order to improve the antibacterial activity and drug delivery efficiency. The synergistic effects of biosynthesize gold loaded with ceftazidium antibiotic at different concentration against MDR bacteria were also investigated. The result showed that ceftazidium-loaded nanoparticles have superior effectiveness compared to native ceftazidium against pseudomonas aeruginosa.

Green Synthesis, Characterization and Biological Activities of Gold Nanoparticles (AuNP) Synthesized Using Extract of Melilotus indicus L.

In this study for the first-time gold nanoparticles (AuNPs) were synthesized (MiAuNPs) using Melilotus indicus L. extract (MiExt) by eco-friendly method for different bioactivity applications. Various analytical techniques used for identifying properties of MiAuNPs include powder X-ray diffraction, UV-Vis absorption spectroscopy, Fourier-Transform Infrared Radiation (FT-IR), and scanning electron microscopy (SEM). The average diameter of MiAuNPs was about 8 nm (crystallite size by XRD was estimated around 13 nm). Antimicrobial activities MiAuNPs revealed significant effect against Gram-positive (Staphylococcus aureus), Gram-negative (Escherichia coli, Proteus mirabilis, and Shigella flexneri) and fungi (Candida albicans). The anticancer activity which may be found in the MiExt as well as extract with MiAuNPs was checked using HepG2 and HeLa cell lines. Results revealed that the MiExt alone was stimulatory to Hela cells growth, while MiAuNPs inhibit it. Both MiExt and MiAuNPs also inhibited HepG2 growth. For larvicidal properties, MiExt and MiAuNPs were tested for larvicidal toxicity effects against 4th instar larvae of the common house mosquito viz., Culex pipiens. MiAuNPs was found more lethal against Cx. pipiens with lower lethal concentration values (LC50 = 333.961 ppm; LC90 = 1433.208 ppm), compared to only MiExt (LC50 = 1815.12 ppm; LC90 = 7164.094 ppm).

Studies of in vitro antioxidant and anti-inflammatory activities of gold nanoparticles biosynthesised from a medicinal plant, Commiphora wightii

ABSTRACT Green synthesis of nanoparticles is one of the recent trends nowadays owing to its reduced toxic effects. Our study is aimed at evaluating the biological potential viz., antioxidant and anti-inflammatory properties of gold nanoparticles (AuNPs) biosynthesised using an aqueous extract of Commiphora wightii. The AuNPs synthesis was preliminarily confirmed by colour change from yellow to purple. Further, AuNPs synthesis was optimised at different ratio, pH and temperature. AuNPs were characterised using spectroscopic and microscopic techniques. FTIR analysis confirmed role of biomolecules in reduction and stabilisation of AuNPs. TEM analysis revealed polydispersed nanoparticles with an average size of 20.2 ± 6.6 nm. In vitroantioxidant activity of AuNPs were evaluated using DPPH, ABTS and H2O2 assays. The AuNPs showed significant radical scavenging ability. In vitro anti-inflammatory activity was studied for inhibition of albumin denaturation, Trypsin, LOX, and hyaluronidase enzymes. The AuNPs exhibited good activity as potent anti-inflammatory agents. Further in vivo studies are needed to explore them as good therapeutic agents.

진공 열처리 과정이 금 나노입자가 코팅된 티타니아 나노튜브의 가시광 원격제어 약물용출 및 항균 활성에 미치는 효과 평가

본 연구의 목적은 진공 열처리 과정이 티타니아 나노튜브 표면에 코팅된 금 나노입자의 가시광 원격제어 항균약물용출 및 항균능에 미치는 영향에 대해서 평가하는 것이다. 100 nm 직경의 티타니아 나노튜브 위에 금 나노입자를 플라즈마 코팅한 후, 진공 열처리 과정을 통하여 균질하게 구형화된 금 나노입자-티타니아 나노튜브 시편을 제작하였다. 확산반사 자외선-가시광선-근적외선 분광광도 측정 결과, 진공 열처리된 금 나노입자-티타니아 나노튜브는 400에서 650 nm의 가시광선 영역에서 강한 광 흡수도를 나타내었다. 전계방출 주사전자현미경 관찰에서는 금 코팅시간이 1분에서 9분으로 증가할수록 나노입자의 크기는 5.59±1.05 nm에서 56.93±10.91 nm로 증가하였고, 종횡비도 1.01±0.31에서 1.55±0.47로 증가하였다. 항균약물(0.1% 테트라사이클린이 포함된 폴리락트산)이 코팅된 금나노입자-티타니아 나노튜브의 가시광선(파장 550 nm) 조사 전·후의 항균약물 용출거동 평가 및 Streptococcus mutans 균을 이용한 항균시험 결과, 가시광 조사를 시행한 실험군의 약물 용출량이 광조사를 하지 않은 대조군의 약물 용출량보다 유의성 있게 높았다(P<0.05). 또한, 가시광 조사를 시행한 시험군에서 유의성 있는 항균효과를 나타내었다(P<0.05). 따라서, 진공 열처리를 이용하여 구형화 시킨 금 나노입자-티타니아 나노튜브 표면처리기술로 가시광 원격제어 약물 용출기능을 가진 항균성 임플란트 재료로서 가능성이 있다고 사료된다.

Physico-chemical and antibacterial properties of gold nanoparticles synthesized using Avicennia marina seeds extract

This study investigated the synthesis and antibacterial activity of gold nanoparticles (AuNPs), produced using aqueous Avicennia marina seed extract. Reaction of the extract with chloroauric acid led to the reduction of auric chloride and the formation of AuNPs within 10 min at 28 °C. The size, shape and elemental composition of the nanoparticles (NPs) was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and UV-visible spectroscopy. Furthermore, the biological capping agents of the NPs were identified via Fourier-transform infrared spectroscopy (FT-IR). The seed extract served as an effective bio-reductant for the synthesis of AuNPs. High-resolution TEM images revealed the NPs to be predominantly spherical in shape, with some hexagonal and rod-shaped particles observed. The AuNPs displayed inhibitory activity against a range of human pathogenic bacterial species: Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa. Complete inhibition was observed at 200 µg/mL. However, E. faecalis was resistant to the NPs. The results suggest that AuNPs synthesised using aqueous seed extracts of mangrove species such as A. marina may serve as broad-spectrum antibacterial agents, particularly for antibiotic resistant strains.

Facile phyto‐mediated synthesis of gold nanoparticles using Eupatorium odoratum leaf extract and its size‐dependent catalytic activity

In this work, gold nanoparticles have been prepared using the leaf extract of Eupatorium odoratum assisted with microwave irradiation. The role of pH on the synthesis of gold nanoparticles has also been studied. At higher value of pH, size of nanoparticles got highly diminished, going below 10 nm. A probable mechanism of formation of such small nanoparticles has been proposed in this Letter. The effects of different parameters such as reaction time, temperature and pH variation on the final morphology of gold nanoparticles have been investigated. The characterisation of the samples has been carried out by transmission electron microscope, UV–Vis absorption spectroscope, Fourier transform infrared spectroscope and zeta potential analysis. Further, a comparative study of catalytic activity of gold nanoparticles of two different sizes was performed by monitoring the reduction of 2,4,6-trinitrophenol. Experimental study showed that smaller nanoparticles are more efficient in their catalytic activity than their larger counter parts. The consistency in sizes and shapes, higher stability and rapid synthesis are the major advantages of this synthesis method. Thus, this procedure of synthesis of gold nanoparticles may offer an attractive alternative to the existing ones and opens a full range of possibilities for various analytical applications.

Diamond Electrodes for High Sensitivity Mercury Detection in the Aquatic Environment: Influence of Surface Preparation and Gold Nanoparticle Activity

AbstractThis work compares polished and unpolished boron doped diamond (BDD) electrodes decorated with two sizes of gold nanoparticles (AuNPs) for use as robust mercury sensors in aquatic environments. The size of the catalytically active AuNPs on the electrode surfaces was demonstrated to have a less significant effect on the sensitivity for mercury detection than the surface preparation of the BDD. The lowest limits of detection were achieved with the polished BDD electrodes, which both detected mercury at a concentration of 1 pM, six orders of magnitude greater sensitivity than the lowest detection limit of 5 μM achieved with an unpolished BDD electrode, and high in comparison with other reported electrode systems.

Gold Nanoparticles for Surface-Enhanced Raman Spectroscopy

This work shows comparative analysis of surface-enhanced Raman scattering (SERS) activity of gold nanoparticles fabricated by chemical synthesis and laser ablation methods. The gold nanoparticles prepared by laser ablation (Au-LA) are more effective for SERS than those prepared chemically (Au-citr). The “analyte on Au film” configuration allows obtaining enhancement of Raman scattering up to 104 in case of Au-LA nanoparticles and up to 102 in case of Au-citr. Also the “sandwich” configuration for Au-LA gives additional enhancement of SERS up to two times, and for Au-citr up to one order, that is consistent with theoretical calculations.

Cytogenetic Activity of Gold Nanoparticles in Germ and Somatic Cells of 129 Mice with a Nonsense Mutation in the DNA Polymerase Iota Gene

In this study, we investigated the cytogenetic effects of single and quadruple exposure of spermatogenic cells and hepatocytes of 129 mice, which have a mutation in the gene that encodes DNA polymerase iota, to ultrasmall gold nanoparticles (GNPs). The combined effects of GNPs and chemical mutagen dipin were evaluated. In all cases, except for the experiment with the quadruple GNP injection, we observed a slight, statistically nonsignificant increase in the frequency of round spermatids with micronuclei compared to the negative control (saline). It is established that, in the intact liver of 129 mice, in all variants of the experiment, GNPs behaved as a potentially cytotoxic agent, as evidenced by the decrease in the frequency of the micronucleated hepatocytes.

A biomimetic synthesis of stable gold nanoparticles derived from aqueous extract of Foeniculum vulgare seeds and evaluation of their catalytic activity

A facile biomimetic approach for the synthesis of gold nanoparticles (AuNPs) using aqueous extract of fennel (Foeniculum vulgare) seeds have been reported in this article. The seeds of F. vulgare are rich in various plant secondary metabolites (phytochemicals) such as polyphenolic acids, flavonoids, and saponins. The phytochemicals of F. vulgare seeds play dual role of reducing and stabilizing agents. The formation of gold nanoparticles was evidenced from the appearance of intense purple color at room temperature with λmax around 550 nm in the UV–Vis absorption spectra. The stable AuNPs were further characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and transmission electron microscopy (TEM) analysis. The synthesized nanoparticles were observed to be polydispersed, spherical and ranged from 10 to 30 nm with an average size of 20 ± 2 nm, as obtained from TEM images. The catalytic activity of gold nanoparticles was investigated by studying the reduction of anthropogenic dyes such as methylene blue (MB) and rhodamine B (Rh-B) with sodium borohydride. Results showed the possible applications of biogenic AuNPs in environment related problems.

Characterization and Antioxidant Activity of Gold Nanoparticles Synthesized using Bambusae Caulis in Taeniam extract

Characterization and Antioxidant Activity of Gold Nanoparticles Synthesized using Bambusae Caulis in Taeniam extract

Antimicrobial Activity of Gold Nanoparticles (AuNPs) on Deterioration of Archeological Gilded Painted Cartonnage, Late Period, Saqqara, Egypt

ABSTRACTA piece of polychrome and gilded cartonnage mask was excavated by the Ministry of Antiquities in Saqqara region. It belongs to the late period. The mask upon mummy presented a gilded face with heavy wig height 30–40 cm was painted with green, black eye brow and red mouth. Cartonnage is a composite material consists of organic support contains many glued layers of linen or papyri that have ground painting layers. It suffers from many deterioration aspects (microbial pigments, and flaking most likely due to inappropriate storage. Examination study was performed to analyze and investigate the ground painting and gilding layer of the cartonnage by optical light microscopy, Scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results confirmed that the degradation factors affecting on the painted, gilded cartonnage was attributed to the direct effects of microbial phenomena, which have led to many deterioration forms (macro- and micro cracks, flaking, coloration, scaling and defoliation microbiological spots). Three Gram-positive bacteria (Bacillus cereus, Bacillus licheniformis and Staphylococcus aureus), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and four fungal species (Aspergillus flavus, Botrytes cinerea, Fusarium moniliforme, and Verticillium albo-atrum) were isolated from archeological gilded painted cartonnage. Antibacterial and antifungal activities of three shapes (rods, spheres and prisms) of gold nanoparticles (AuNPs) were tested against the isolated deteriorated microbial species. The rod-shaped gold nanoparticles have high potential antibacterial and antifungal activity reaching to the maximum significant inhibition (8- and 9-cm inhibition zones) against the most sensitive bacterial and fungal species (B. cereus and A. flavus, respectively) accompanied with leakage of protein and nucleic acid, sugars and electrolytes. Disturbance in the blood picture of guinea pigs infected with the most resistant species (P. aeruginosa and F. moniliforme) were showed. The rod-shaped gold nanoparticles were safe and successful in curing the tested inoculated guinea pigs.

Nucleation of Polypropylene Crystallization with Gold Nanoparticles. Part 2: Relation between Particle Morphology and Nucleation Activity

ABSTRACTThe influence of gold nanoparticle morphology on nucleation of isotactic polypropylene (PP) crystallization was investigated. Previous experiments indicated certain nucleation activity of gold nanoparticles, varying with their size. In this work, eight types of gold micro/nanoparticles were used: vacuum-sputtered nanostructures (nanoparticles, nanoislands, and nanolayers), chemically prepared isometric gold nanocrystals (5, 20, and 100 nm diameters), and two types of gold microcrystals with well-developed crystal facets [with (100) and (111) facets, respectively]. To minimize the effect of particle agglomeration, we used our recently introduced sandwich method, in which the nucleating agent was deposited between thin PP films and the nucleation was evaluated by polarized light microscopy (PLM), X-ray scattering (WAXS), and differential scanning calorimetry (DSC). The nucleation activity of Au particles in PP was lower than it might be expected from the previous studies and depended on their morphology. The nucleation activity of Au microcrystals with well-developed facets was higher than the activity of non-faceted Au nanocrystals.

English

English

Antimicrobial activity of gold nanoparticles (AuNPs) on deterioration of archeological gilded painted cartonnage, late period, Saqqara, Egypt.

ABSTRACTA piece of polychrome and gilded cartonnage mask was excavated by the Ministry of Antiquities in Saqqara region. It belongs to the late period (664 – 332 BC). The mask upon mummy presented a gilded face with heavy wig height 30–40 cm was painted with green, black eye brow and red mouth. Cartonnage is a composite material consists of organic support contains many glued layers of linen or papyri that have the ground painting layers. It suffers from many deterioration aspects (microbial pigments, and flaking most likely due to inappropriate storage. Examination study was performed to analyze and investigate the ground painting and gilding layer of the cartonnage by Optical light microscopy, Scanning electron microscopy (SEM) equipped with energy dispersive × ray analysis, fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results confirmed that the degradation factors affecting on the painted, gilded cartonnage was attributed to the direct effects of microbial phenomena, which have led to many deterioration forms (macro- and micro cracks, flaking, coloration, scaling and defoliation microbiological spots). Three Gram-positive bacteria (Bacillus cerus, Bacillus licheniformis and Staphylococcus aureus), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and four fungal species (Aspergillus flavus, Botrytes cinerea, Fusarium moniliforme, and Verticillium albo-atrum) were isolated from archeological gilded painted cartonnage. Antibacterial and antifungal activities of three shapes (rods, spheres and prisms) of gold nanoparticles (AuNPs) were tested against the isolated deteriorated microbial species. The rod shaped gold nanoparticles have high potential antibacterial and antifungal activity reaching to the maximum significant inhibition (8 and 9 cm inhibition zones) against the most sensitive bacterial and fungal species (B. cerus and A. flavus, respectively) accompanied with leakage of protein and nucleic acid, sugars and electrolytes. Disturbance in the blood picture of guinea pigs infected with the most resistant species (P. aeruginosa and F. moniliforme) were showed. The rod shaped gold nanoparticles was safe and successful in curing the tested inoculated guinea pigs.

Catalytic properties of gold nanoparticles in H2—D2 exchange and ortho—para hydrogen conversion

Gold nanoparticles of 3.8, 4.6, and 19.4 nm size, unlike the bulk metal, can adsorb hydrogen and catalyze the deuterium—protium exchange in the 77—523 K range. It has been shown that as the particle size decreases, the specific catalytic activity increases. The exceptionally high catalytic activity of gold nanoparticles in the ortho—para hydrogen conversion with respect to the deuterium—hydrogen exchange may indicate that at low temperatures the nanoparticles exhibit magnetic properties.

Immuno-Potentiating Activity of Gold Nanoparticles on Experimental Animal Models

Immuno-Potentiating Activity of Gold Nanoparticles on Experimental Animal Models Gold nanoparticles (GNPs) have found their application in various fields of biomedical science. The immunological behaviour portrayed by GNP has been of great interest and not studied well. In the present study, the immuno potentiation property of GNP (40-50 nm) has been explored by studying the effect on immuno competent cells and immuno deficient animal models. Single dose exposure of GNP was given to male albino mice and total count of spleen, lungs and thymic lymphocyte and peritoneal macrophage was studied. Immuno deficient animal models were established (using UV rays and cyclophosphamide) and effect of GNP was studied through the total WBC count, macrophage count and haemagglutination titre value. It was observed that single dose exposure of GNP resulted a significant rise in WBC count, lung, spleenic and thymic lymphocyte count. In UV and cyclophosphamide (CP) induced immuno deficient animal model, GNP showed immuno stimulation by increasing WBC count significantly and restoration of macrophage count compared to the immuno deficient group. Humoral immunity of immuno deficient animals was decreased by UV and CP, observed through low haemagglutination titer value. GNP was found to increase the circulating antibody titre value in UV and CP induced immuno deficient animals. This study indicated that GNP has immuno potentiation capacity in immuno compromised and immuno deficient animal models. This study could bring forward new dimensions in combating immuno deficiency related problems (due to microbial infections, chemotherapy, AIDS) by GNP. The immuno potentiation property of GNP may be utilized in certain immuno deficient pathophysiological condition and may provide double protection. Further detailed study at molecular level (involving immunomodulatory markers) may enrich the concept.