Green synthesis of silver nanoparticles using Capsicum annuum L. extract (original) (raw)
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International Journal of Nanomedicine , 2018
Silver nanoparticles (AgNPs) are of great interest due to their unique and controllable characteristics. Different synthesis methods have been proposed to produce these nanoparticles, which often require elevated temperatures/pressures or toxic solvents. Thus, green synthesis could be a replacement option as a simple, economically viable and environmentally friendly alternative approach for the synthesis of silver nanoparticles. Here, the potential of the walnut green husk was investigated in the production of silver nanoparticles. An aqueous solution extracted from walnut green husk was used as a reducing agent as well as a stabilizing agent. Then, the synthesized nanoparticles were characterized with respect of their anticancer, antioxidant, and antimicrobial properties. Results showed that the synthesized nanoparticles possessed an average size of 31.4 nm with a Zeta potential of -33.8 mV, indicating high stability. A significant improvement in the cytotoxicity and antioxidant characteristics of the green synthesized Ag nanoparticles against a cancerous cell line was observed in comparison with the walnut green husk extract and a commercial silver nanoparticle (CSN). This could be due to a synergistic effect of the synthesized silver nanoparticles and their biological coating. AgNPs and the extract exhibited 70% and 40% cytotoxicity against MCF-7 cancerous cells, respectively, while CSN caused 56% cell death (at the concentration of 60 μg/mL). It was observed that AgNPs were much less cytotoxic when tested against a noncancerous cell line (L-929) in comparison with the control material (CSN). The free radical scavenging analysis demonstrated profound anti-oxidant activity for the synthesized nanoparticles in comparison with the extract and CSN. It was also detected that the synthesized AgNPs possess antibacterial activity against nosocomial and standard strains of both Gram-positive and Gram-negative bacteria (minimum inhibitory concentration =5–30 μg/mL). These findings imply that the synthesized nanoparticles using green nanotechnology could be an ideal strategy to combat cancer and infectious diseases.
Green synthesis of silver nanoparticles and their antibacterial activities
Original article, 2022
Nanotechnology offers a solution to bacterial antibiotic resistance, which poses a serious threat to global health. Green synthesis of metallic nanoparticles is gaining increasing attention due to its environmental benefits. This study aimed to biosynthesize silver nanoparticles (AgNPs) by microwave irradiation through silver nitrate reduction using starch and microalgae biomass; characterize them using UV-visible spectroscopy, scanning electron microscopy-energy-dispersive X-ray microanalysis, and X-ray diffraction; and evaluate their antibacterial activity against Escherichia coli, Bacillus clausii, and Staphylococcus aureus using disk diffusion and broth dilution methods. Synthesized AgNPs showed a single peak related to surface plasmon resonance at 430 nm. Size range of spherical AgNPs was 40-150 or 90-400 nm for starch-or biomass-mediated NPs, respectively. Biomassmediated AgNPs exhibited antibacterial activity with the inhibition zones of 8, 12, and 10.5 mm against E. coli, B. clausii, and S. aureus, respectively; those starch-mediated showed inhibition of 7, 13, and 12 mm, respectively. AgNPs' minimum inhibitory concentrations were 6.25 μg•mL −1 toward both E. coli and S. aureus and 12.5 μg•mL −1 against B. clausii when using starch in biosynthesis, whereas they were 19.6 μg•mL −1 against both E. coli and S. aureus and 9.81 μg•mL −1 toward B. clausii when using biomass. Synthesized AgNPs have promising antibacterial potential.
Int. J. Environ. Res. Public Health , 2013
Our research focused on the production, characterization and application of silver nanoparticles (AgNPs), which can be utilized in biomedical research and environmental cleaning applications. We used an environmentally friendly extracellular biosynthetic technique for the production of the AgNPs. The reducing agents used to produce the nanoparticles were from aqueous extracts made from the leaves of various plants. Synthesis of colloidal AgNPs was monitored by UV-Visible spectroscopy. The UV-Visible spectrum showed a peak between 417 and 425 nm corresponding to the Plasmon absorbance of the AgNPs. The characterization of the AgNPs such as their size and shape was performed by Atom Force Microscopy (AFM), and Transmission Electron Microscopy (TEM) techniques which indicated a size range of 3 to 15 nm. The anti-bacterial activity of AgNPs was investigated at concentrations between 2 and 15 ppm for Gram-negative and Gram-positive bacteria. Staphylococcus aureus and Kocuria rhizophila, Bacillus thuringiensis (Gram-positive organisms); Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhimurium (Gram-negative organisms) were exposed to AgNPs using Bioscreen C. The results indicated that AgNPs at a concentration of 2 and 4 ppm, inhibited OPEN ACCESS Int. J. Environ. Res. Public Health 2013, 10 5222 bacterial growth. Preliminary evaluation of cytotoxicity of biosynthesized silver nanoparticles was accomplished using the InQ™ Cell Research System instrument with HEK 293 cells. This investigation demonstrated that silver nanoparticles with a concentration of 2 ppm and 4 ppm were not toxic for human healthy cells, but inhibit bacterial growth.
Green Synthesis of Ag Nanoparticles and Their Performance towards Antimicrobial Properties
Sains Malaysiana
Green synthesis is a forthcoming trend in the nanotechnology field where classical methods of synthesis are now replaced by inexpensive and eco-friendly methods. In this study, a green method has been developed for the synthesis of silver nanoparticles (AgNPs) where AgNPs were synthesised using water-based facile hydrothermal method. Silver nitrate (AgNO 3) and polyvinylpyrrolidone (PVP) were used as precursor and reducing agents to produce AgNPs. The molar ratio effect of the precursor and stabiliser, its reaction temperature and reaction time were investigated. X-ray Powder Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and UV-Vis Spectrometry were used to characterise the AgNPs. The as-synthesized AgNPs with different molar ratios of the precursor to stabiliser were tested for antibacterial activities using Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli). All the AgNPs samples exhibited antibacterial activities that were stronger against Gram-negative bacteria, as compared with Gram-positive bacteria. The diameter of the zone of inhibition (ZOI) increased with the increase of the AgNO 3 : PVP molar ratios. The results obtained proved that uniform AgNPs synthesized via green techniques have a high potential of influencing applications involving antimicrobial properties.
Antibacterial and Cytotoxic Potential of Biosynthesized Silver Nanoparticles by Some Plant Extracts
Nanomaterials
The provision of nanoparticles using biogenic material as a part of green chemistry is an attractive nanotechnology. The current research aimed to test the antimicrobial and cytotoxic efficacy of silver nanoparticles synthesized by extracts of Phoenix dactylifera, Ferula asafetida, and Acacia nilotica as reductant and stabilizing agents in silver nanoparticle formation. Synthesized nanoparticles were evaluated for their antimicrobial activity against Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa and Escherichia coli (Gram-negative) using an agar well diffusion assay. Furthermore, cytotoxic ability was investigated against LoVo cells. The potential phyto-constituents of plant extracts were identified by Fourier-transform infrared spectroscopy (FT-IR) techniques. Field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), and zeta potential analyzed the size and morphology of the biogenic nanoparticles. The current study revealed the ability of the tested plant extract to convert silver ions to silver nanoparticles with an average size that ranged between 67.8 ± 0.3 and 155.7 ± 1.5 nm in diameter. Biogenic AgNPs showed significant antibacterial ability (10 to 32 mm diameter) and anticancer ability against a LoVo cell with IC50 ranged between 35.15-56.73 µg/mL. The innovation of the present study is that the green synthesis of NPs, which is simple and cost effective, provides stable nano-materials and can be an alternative for the large-scale synthesis of silver nanoparticles.
Canadian Journal of Biotechnology
In the present study we have made an attempt to develop an eco-friendly, cheap and convenient biological (green) method for the synthesis of silver nanoparticles (AgNPs) using the cell extract of the cyanobacterium Nostoc sp. strain HKAR-2. Their anticancerous, antifungal and antibacterial properties were also studied against MCF-7 cells, two fungal strains (Aspergillus niger and Trichoderma harzianum) and two plant bacterial strains (Ralstonia solanacearum and Xanthomonas campestris), respectively. The structural, morphological and optical properties of green synthesized AgNPs were determined by UV-VIS spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, transmission electron microscopy selected area electron diffraction (TEM-SAED) and scanning electron microscopy (SEM). Spectroscopic analysis showed the peak at 419 nm due to the reduction of AgNO3 into silver ion by cyanobacterial extract indicating surface plasmon resonance (SPR) of the synthesized AgNPs. The XRD pattern of AgNPs showed the characteristic Bragg peaks at (111), (200), (220) and (311) facets of the face centre cubic (fcc) confirming their crystalline nature. FTIR analysis revealed that proteins and amino acids are responsible for the reduction of AgNO3 into Ag + as well as for the stability of nanoparticles. Zeta potential confirmed that the charge on the nanoparticles is 1.80 mV which indicates the presence of stable nanoparticles. The results of SEM and TEM confirmed the large agglomerated shape of AgNPs with size ranging between 51-100 nm. The AgNPs showed a dose-dependent cytotoxic activity against human breast cancer MCF-7 cells with IC50 of 27.5 µg/ml. They also exhibited excellent antibacterial and antifungal activities.
Novel Research in Microbiology Journal
Applications of nanotechnology in different areas of research have expanded over the last years. Silver nanoparticles (AgNPs) have beneficial effects as antimicrobials, antioxidants and/or anticancer. Yet, one of the major limitations of their use was employing toxic chemicals as reducing agents. Biosynthesis was advantageous over the physical and chemical synthesis. The obtained nanoparticles were characterized using the High-Resolution Transmission Electron Microscope. Disc diffusion method was used to evaluate the antibacterial activity of AgNPs against Bacillus subtilis, Escherichia coli, Neisseria gonorrhoeae, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus faecalis. Cytotoxic activity of biosynthesized AgNPs was tested against humane breast cancer cell line (MCF-7). Results of characterization showed that AgNPs were irregular spherical in shape, with average diameter of 27.41nm, and width of 4.36nm. The antibacterial assay showed that Portulacaria afra extract had no inhibitory potential against the tested bacteria. However, both AgNO 3 and AgNPs exhibited recognized inhibitory potency against all tested bacteria. AgNPs exhibited wider inhibition zones than AgNO 3. Cytotoxicity test revealed that green synthesized AgNPs had inhibitory activity against cancer cell line (MCF-7) which was concentration dependent, with IC 50 of 75.40 µmole. The aims of the present work were to study the possible green synthesis of AgNPs using P. afra aqueous leaf extract as a reducing agent; to characterize them, to investigate the antibacterial potency and cytotoxic potential of these biosynthesized AgNPs.
Journal of Scientific Research in Science, 2018
The present study reported a facile and rapid biosynthesis method for gold nanoparticles (GNPs) silver nanoparticles (AgNPs) and bimetallic heterogeneous sliver-aurum nanoparticles(AgAuNPs) using the leaves of Gmelinaarborea (ROXB) (Family Verbenaceae) extract. The aqueous leaves extract was used as biotic reducing and stabilizing agent of the growing nanoparticles. The synthesized gold nanoparticles (AuNPs),silver nanoparticles (AgNPs) and silver-gold core-shell nanoparticles(AgAuNPs) were characterized using UV-Vis spectroscopy (UV-Vis), Fourier transform infrared spectroscopy, (FT-IR), X-ray diffraction (XRD),transmission electron microscopy (TEM)and thermal gravimetric analyses (TGA). Several factors such as the extract amount, contact time and solution pH, as possible influences; were investigated to obtain the optimized synthesis conditions. The antimicrobial activity study revealed that while the aqueous extract at concentrations of0.8 and 4% (w/v) showed no effect on the antimicrobial activity, the produced nanoparticles, AuNPs, AgNPs and AgAuNPs inhibited thegrowth of Gram positive bacteria (Bacillus subtillus, Staphylococcus aureus), Gram negative bacteria (E. Coli and Pseudomonas aeruginosa) and Fungi (Candida albicansand Aspergillusniger). The cytotoxic activity against hepatocellular carcinoma (HePG2)was alsoevaluated.
Arhiv Za Higijenu Rada I Toksikologiju, 2023
Silver nanoparticles (AgNPs), which have recently gained attention due to their antimicrobial activity, can also be produced by green synthesis. The aims of this study were to (i) characterise green synthesized AgNPs using microwave-assisted aqueous extracts of Galium aparine (G-AgNPs) and Helichrysum arenarium (H-AgNPs) and (ii) investigate the combined antimicrobial effects of the G-and H-AgNPs in different ratios. Nanoparticle formation and reactions were determined with UV-Vis spectroscopy. The G-AgNPs were 52.0±10.9 nm in size, with a 0.285±0.034 polydispersity index (PDI), and a-17.9±0.9 mV zeta potential. For H-AgNPs these characteristics were 23.9±1.0 nm, 0.280±0.032, and-21.3±2.7 mV, respectively. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the particles were monodisperse and spherical. The Fourier transform-infrared spectroscopy (FT-IR) results showed the presence of reducing agents that stabilised the AgNPs. Three different nanoformulations (NF-1, NF-2, and NF-3) were prepared by combining these two synthesised nanoparticles in different ratios and their antimicrobial activity was tested against E. coli, S. aureus, C. albicans, and A. flavus. Our study is the first to show that combining AgNPs from two different biological sources can produce effective nanoformulations with improved antibacterial activity against E. coli and S. aureus. These nanoformulations showed lower minimum inhibitory concentrations (31.25 µg/mL against E. coli with all NFs; 62.5 µg/mL for NF-1 and 125 µg/mL for NF-2/3 against S. aureus) than G-AgNPs (62.5 µg/mL for E. coli) or H-AgNPs (125 µg/mL for S. aureus) alone. Their high combined inhibitory effect against E. coli (NF-1-3) was synergistic and against S. aureus (NF-2 and NF-3) potentially additive. Considering such promising results, we believe our study provides some direction for new research and strategies in antimicrobial therapeutics.