Leaf Extract-mediated Silver Nanoparticles Research Articles

Evaluation of antibacterial activity, in-vitro cytotoxicity and catalytic activity of biologically synthesized silver nanoparticles using leaf extracts of Leea macrophylla

Nanotechnology has become a cutting-edge field of research that has emerged as an interdisciplinary research area and contributes to almost every field of science. With the increasing demand for sustainable greener products, attention has recently been focused on green nanotechnology. This study manifested the aptitude of Leea macrophylla (LM) leaf extract, fortified with phytochemicals, to biosynthesize silver nanoparticles (AgNPs) for the first time. As soon as the AgNPs were biosynthesized, they immediately changed color, and the distinctive surface plasmon resonance (SPR) occurred at 420 nm in the Ultraviolet–Visible spectrum, proving that the biosynthesis had been successful. Fourier Transform Infrared Spectroscopy (FTIR) was used to examine the phytochemicals present in the LM leaf extract, those are accountable for the formation and stabilization of AgNPs. The Transmission Electron Microscope (TEM) revealed the formation of quasi spherical silver nanoparticles with an average diameter of 22.77 nm. Synthesized nanoparticles were further characterized by X-ray diffraction (XRD), Field Emission Scanning Electron microscope (FESEM), Energy Dispersive X-ray (EDX), Dynamic Light Scattering (DLS) and Thermogravimetric analysis (TGA). The production of AgNPs with high metal content from LM leaf extract exhibited encouraging results. The LM leaf extract mediated silver nanoparticles evinced significant antibacterial and catalytic activities. The cytotoxicity effects of biosynthesized AgNPs were tested on brine shrimps.

Elsholtzia ciliata Leaf Extract Mediated Silver Nanoparticles: Synthesis and their Antioxidant, Antidiabetic and Anticancer Activities

This study deals with silver nanoparticle synthesis utilizing the leaf extract of the medicinal plant Elsholtzia ciliata and evaluated its antioxidant, antidiabetic and anticancer activities. The characterization of the synthesized E. ciliata silver nanoparticles (Ec-AgNPs) were done by using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The formation of face-centred cubic silver nanocrystals was confirmed by XRD data. During the formation of Ec-AgNPs, the phytochemicals present in the leaf extract act as reducing and capping agents as confirmed by FTIR spectra. The zeta potential and polydispersity index values from DLS measurements were -16.4 mV and 0.261, respectively. The high content of flavonoids, phenols, tannins and coumarins was confirmed by the phytochemical studies of the plant extract. The antioxidant activity was shown by the synthesized Ec-AgNPs. The inhibition of carbohydrate digestive enzyme α-glucosidase with IC50 values of 29.32 ± 0.42 μg/mL was found for the biosynthesized silver nanoparticles. MTT assay was performed on A549, HCT116 and HeLa Cell lines for evaluation of the antiproliferative activities of the Ec-AgNPs and have shown IC50 values of 189 ± 8.7, 192.5 ± 0.5 and 51.7 ± 7.8 μg/mL in A549, HCT116 and HeLa Cell lines, respectively. These findings proved that the biosynthesized Ec-AgNPs had good antioxidant, antidiabetic and anticancer activities and hence can be a competent candidate for an antioxidant, antidiabetic and anticancer agents in the pharmaceutical sector.

Azadirachta indica leaf extract mediated silver nanoparticles impregnated nano composite film (AgNP/MCC/starch/whey protein) for food packaging applications

In order to be used in food packaging, the study aims to develop a composite film based on microcrystalline cellulose (MCC) and coated with silver nanoparticles (AgNPs). The MCC was derived from sugar cane bagasse. Protein, starch, and poly-ethylene glycol 1500 (PEG-1500) are employed to improve the tensile strength, flexibility, and durability of the packaging film. The AgNPs was synthesized by a green route employing Azadirachtaindica leaf extract as reducing agent. The determined average crystallite size of AgNPs was seen at 20 nm. The X-ray diffraction (XRD) studies of the final film prepared have an elevated peak with a crystallinity of 37.5%. The scanning electron microscopic images (SEM) of the AgNPs and the prepared samples, reveal their surface morphology. The Fourier transform infrared spectroscopic studies (FT-IR) disclose the functional group changes during the film preparation. The antibacterial activity of the amalgamated AgNPs against five bacterial pathogens studied was found to be highly active against tested food pathogens, except for Proteus vulgari. When coated over a vegetable, the produced nanocomposite film displayed an increased shelf life for the vegetable by limiting the decay impact caused by food pathogens. According to the findings, the AgNPs-impregnated MCC/Starch/Whey protein has the potential to be employed as an antimicrobial packaging material.

Synthesis, characterization and photocatalytic application of Sophora mollis leaf extract mediated silver nanoparticles

Abstract This study reports green synthesis and characterization of silver nanoparticles (Ag NPs) from Sophora mollis leaf extract. The use of S. mollis extract for preparation of Ag NPs was investigated using different techniques. Dark brown color indicates formation of nanoparticles. Fourier transform infra-red (FTIR) analysis revealed that plant extract act as a reducing and capping agent. Morphological aspects of Ag NPs were ascertained by means of SEM studies. Energy dispersive and FTIR spectroscopy results showed chemical composition and plant extract functionality respectively. X-ray diffraction (XRD) analysis showed particle size of 70 nm. Antibacterial activity of NPs was investigated by disc diffusion and minimum inhibitory concentration method. Antioxidant activity of NPs was shown by DPPH assay. The photo catalytic efficiency of synthesized Ag NPs was evaluated by degradation of methylene blue (MB) dye under UV irradiation. Ag NPs degraded MB dye up to 88% in 160 min. It is concluded that these NPs could be employed for degradation of toxic industrial effluents. Result proved the green synthesis of Ag NPs from S. mollis extract is clean, economical and safe method.

Argyreia nervosa (Samudra pala) leaf extract mediated silver nanoparticles and evaluation of their antioxidant, antibacterial activity, in vitro anticancer and apoptotic studies in KB oral cancer cell lines

In the present investigation, green synthesis of silver nanoparticles (AgNPs) was carried out using aqueous leaf extract of Argyreia nervosa. The results of the spectral characterisation have revealed that the surface Plasmon resonance band was observed at 421 nm confirms the formation of AgNPs. The Fourier Transform Infra-red Spectroscopy result shows the reduction of silver nitrate into AgNPs by the reduction of different functional groups. Transmission Electron Microscope analysis revealed that the particles are roughly spherical and poly-disperse in shape and size, the particles are within the size range of 10–55 nm. Dynamic Light Scattering revealed that the nanoparticles were also within the range of 10–50 nm, An-AgNPs have a high negative zeta potential value of −38.9 mV. An-AgNPs showed efficient free radical scavenging activity and showed excellent antimicrobial activity. Anti-proliferative and cytotoxic effect of An-AgNPs was carried out by MTT assay against KB oral cancer cells, the IC50 value of An-AgNPs is 58.64 µg/ml. The cell's growth is arrested at the G2/M phase, so the An-AgNPs activated the Caspase 3 pathway which leads to the Apoptosis of KB oral cancer cells. So it is concluded that the green synthesised An-AgNPs have manifold functions.

Biogenic synthesis, characterization and antimicrobial activity of Ixora brachypoda (DC) leaf extract mediated silver nanoparticles

The present investigation was aimed at the evaluation of synthesis, characterization and antimicrobial activity of Ixora brachypoda DC. leaf extract mediated silver nanoparticles (AgNPs). The AgNPs were characterized by UV–Visible (UV–Vis) spectrophotometer, Fourier transform infrared spectroscopy (FTIR), Atomic force microscopy (AFM), Scanning electron microscopy (SEM) with Energy dispersive X-ray spectrometry (EDS), Transmission electron microscopy (TEM), Zeta potential and X-ray diffractometry (XRD). Finally, the antimicrobial activity of synthesized AgNPs was investigated against pathogenic microorganisms. The absorption peak, obtained at 423 nm in UV–Vis analysis, confirmed the synthesis of AgNPs and the presence of biological functional groups involved in the capping and stabilization were determined by FTIR analysis. The other characterizations revealed the details about the AgNPs as spherical, poly-dispersed and size ranging from 18 to 50 nm with an average diameter of 27.76 nm. The zeta potential was calculated to be −30.4 mV and the typical Bragg’s planes in the metallic silver range indicated the confirmation of AgNPs formation. The in-vitro analysis confirmed the antimicrobial potential of I. brachypoda leaf aqueous extract synthesized AgNPs, which effectively inhibited the growth of pathogens and it can be concluded that the I. brachypoda AgNPs can be used as broad-spectrum antimicrobials against multi-drug resistant microbial pathogens.

Evaluation of saponin-rich/poor leaf extract-mediated silver nanoparticles and their antifungal capacity

AbstractOne-pot green synthesis of silver nanoparticles (AgNPs) has attracted much attention due to its simplicity, high feasibility in scaling up production, abundantly renewable sources, and environmental friendliness. Herein, Ocimum tenuiflorum and Phyllanthus urinaria leaf extracts (OT-ext and P.uri.ext, respectively) were chosen as reacting agents with rich and poor saponins to fabricate two biogenic AgNPs and characterize them. OT-AgNPs were simply and successfully generated by OT-ext. Ultraviolet-visible spectra showed the peak centered at 434 nm, which confirmed the presence of AgNPs after an 8-h reaction. FT-IR showed the organic functional groups (OH, C═O, C═C, CH, and COC) capping the surface of OT-AgNPs, which agreed with energy-dispersive X-ray spectroscopy analysis exhibiting the composition containing C, O, and Ag. Transmission electron microscopy micrographs revealed that OT-AgNPs possess spherical morphology, with a size range of 5–61 nm, and the majority having a small size within that range. In comparison, P.uri.AgNPs formed by P.uri.ext had a size distribution in a similar range, but the P.uri.AgNP diameter shifted toward larger sizes. Further, OT-AgNPs and P.uri.AgNPs showed an effective antifungal ability against Fusarium oxysporum, Aspergillus niger, and Aspergillus flavus. Overall, it was found that the rich saponins in the extracts lead to the formation of smaller AgNPs, but all extract-mediated AgNPs with a size less than 100 nm can act as a fungicide for various applications.

Annona muricata assisted biogenic synthesis of silver nanoparticles regulates cell cycle arrest in NSCLC cell lines

With plenteous accessible therapeutics, lung cancer endures a preeminent cause of the worldwide fatality. Apart from medical advancements, various plant parts are still used to treat cancer based on proven tradition. The present study focuses on analysing the anticancer efficacy of silver nanoparticles coupled with the aqueous leaf extract of Annona muricata. Nanoparticles play a momentous role in drug delivery due to their size and high surface to volume ratio and are with fewer side effect when phytofabricated. Annona muricata aqueous leaf extract mediated silver nanoparticles were characterized using UV visible spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction and Zeta-sizer. Their antiproliferative potency was analysed by studying the mRNA and protein expressions of various apoptotic, anti-apoptotic and cell cycle regulatory genes. In addition, the cell cycle regulation was further confirmed using flow cytometry. The nanoparticles were found to be spherical shaped crystals with 80 ± 6.3 nm as average size and 6 µg/ml as inhibitory concentration 50 (IC50) on A549 human lung cancer cell line. It was observed that the nanoparticles efficiently induced apoptotic protein expression with a simultaneous suppression of anti-apoptotic protein. The results demonstrate activation of an intertwined intrinsic apoptotic pathway via caspases and the death receptors. The observations infer that the nanoparticles show excellent anticancer efficacy than the crude extract of Annona muricata leaves. Hence these nanoparticles would be a promising adjuvant for treating non- small cell lung cancer.

Effective Inhibition of Phytopathogenic Microbes by Eco-Friendly Leaf Extract Mediated Silver Nanoparticles (AgNPs).

This study was aimed at producing the eco-friendly, safe, and inexpensive silver (Ag) nanoparticles (NPs) and assessing its antimicrobial activity. Fungal pathogens isolated from diseased leaves and fruits of brinjal and bacterial pathogen obtained from a culture collection were used in this study. Green synthesis of AgNPs was performed and optimized using Azadirachta indica leaf extract. The newly synthesized AgNPs (λmax = 437nm) showed isotropism in size (crystal size/diameter: 21/29 ± 5nm) and morphology under transmission and scanning electron microscopy and energy dispersive X-ray analysis. The fourier transform infrared spectroscopy data suggested the role of various aliphatic/aromatic moieties and proteins in AgNPs stabilization. The AgNPs reduced the growth of Penicillium sp. maximally by 92% after 6days. The sensitivity of test fungi towards AgNPs followed the order: Penicillium sp. (92%) > Fusarium sp. (89%) > Aspergillus sp. (69%). Exposure of Ralstonia solanacearum to AgNPs (MIC/MBC 200/400µgml-1) displayed damaged cellular envelopes, bulging of cells, and pit formation. The nucleic acid discharge showed a progressive increase from 8 to 34% (r2 = 0.97). The cellular metabolic activity and surface adhering ability of R. solanacearum were completely lost at 400 µgAgNPs ml-1. Results suggested that the AgNPs synthesized in this study had enough anti-pathogenic potential and could inexpensively and safely be used as a promising alternative to agrochemicals. Moreover, the findings observed in this study is likely to serve as an important indicator for the development of effective nano-control agents which in effect would help to manage some deadly phyto-pathogens capable of causing heavy losses to agricultural production systems. Effective inhibition of phytopathogenic microbes by eco-friendly neem leaf extract mediated silver nanoparticles (AgNPs).

Spectroscopic, microscopic characterization of Cannabis sativa leaf extract mediated silver nanoparticles and their synergistic effect with antibiotics against human pathogen

Silver nanoparticles (SNPs) are successfully synthesized from aqueous silver nitrate (AgNO3) through a simple novel route using the leaf extract of Cannabis sativa. The results obtained from UV–visible spectroscopy, FTIR (Fourier transform-infrared) spectroscopy, XRD (X-ray diffraction), DLS (dynamic light scattering) SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy), TEM (transmission electron microscopy), SAED (selected area electron diffraction) and AFM (atomic force microscopy) indicate towards the formation of stable, spherical and crystalline SNPs in the size range of 13–25 nm with absorbance peak at 392 nm. Further, various antibiotic alone and with SNPs have been tested against different pathogenic microorganisms and the results show that control of pathogenic microorganisms is more when antibiotics are mixed with SNPs.

Study of dislocation density (defects such as Ag vacancies and interstitials) of silver nanoparticles, green-synthesized using Barleria cristata leaf extract and the impact of defects on the antibacterial activity

Abstract In this work, we have successfully synthesized highly biocompatible and functionalized B. cristata mediated silver nanoparticles (Ag NPs) with different quantities of its extract for the estimation of impact of defects and the antibacterial activity. The properties of synthesized Ag NPs with B. cristata leaf extract was subjected into various studies such as structural, optical, spectral, surface morphological and antibacterial activities. XRD analysis reveals the crystalline structure and particle size of Ag NPs. The Surface Plasmon Resonance band was measured and observed by UV–Visible spectral studies. The defects such as Ag vacancies and interstitials were calculated by dislocation density. The FE-SEM and TEM images display the shape of particle size. The HR-TEM image shows Surface morphology, high crystallinity with lattice fringes and size of the particles. The element (presence of Ag crystal) analyzed by Energy Dispersive X-ray Spectroscopy (EDX). B. cristata leaf extract mediated silver nanoparticles, which possess very good antimicrobial activity against both E. coli and S. aureus which was confirmed by disc diffusion method.

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Silver Nanoparticles as Antibacterial and Anticancer Materials Against Human Breast, Cervical and Oral Cancer Cells.

Silver nanoparticles contribute a giant share to the realm of modern nanobiotechnology. Their utility as antimicrobial agents is also well documented. Green synthesis of nanoparticle has several advantages over its chemical synthesis. In the present study, Thuja occidentalis leaf extract mediated silver nanoparticles were prepared without using a stabilizing agent and tested for their anticancer and anti-microbial activity. Thuja occidentalis leaf extract mediated silver nanoparticles were prepared under ambient conditions which showed a narrow size distribution within the range of 10–15 nm, with average particle size of 12.7 nm. Interestingly, these nanoparticles exhibited anti-cancer activity against human breast (MCF 7, MDA MB 231) and cervical cancer (HeLa) as well as mouth epidermoid carcinoma (KB) cell lines at a concentration range of 6.25–50 μg/mL. Contrarily, they are compatible with human peripheral blood mononuclear cells and rat hepatocytes. Moreover, their efficient inhibitory effect was witnessed against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Pseudomonas aeruginosa with inhibitory concentration at 5–10 μg/mL. The prepared nanoparticles were highly biocompatible and have strong potential in the development of non-toxic chemotherapy with antibacterial attributes.

Lantana camara leaf extract mediated silver nanoparticles: Antibacterial, green catalyst

Silver nanoparticles (AgNPs) have been synthesized by Lantana camara leaf extract through simple green route and evaluated their antibacterial and catalytic activities. The leaf extract (LE) itself acts as both reducing and stabilizing agent at once for desired nanoparticle synthesis. The colorless reaction mixture turns to yellowish brown attesting the AgNPs formation and displayed UV–Vis absorption spectra. Structural analysis confirms the crystalline nature and formation of fcc structured metallic silver with majority (111) facets. Morphological studies elicit the formation of almost spherical shaped nanoparticles and as AgNO3 concentration is increased, there is an increment in the particle size. The FTIR analysis evidences the presence of various functional groups of biomolecules of LE is responsible for stabilization of AgNPs. Zeta potential measurement attests the higher stability of synthesized AgNPs. The synthesized AgNPs exhibited good antibacterial activity when tested against Escherichia coli, Pseudomonas spp., Bacillus spp. and Staphylococcus spp. using standard Kirby–Bauer disc diffusion assay. Furthermore, they showed good catalytic activity on the reduction of methylene blue by L. camara extract which is monitored and confirmed by the UV–Vis spectrophotometer.

Synthesis, Characterization of <I>Euphorbia fusiformis</I> Leaf Extract Mediated Silver Nanoparticles and Its Antibacterial Potential

Synthesis, Characterization of <I>Euphorbia fusiformis</I> Leaf Extract Mediated Silver Nanoparticles and Its Antibacterial Potential

One step green synthesis and anti-microbial and anti-biofilm properties of Psidium guajava L. leaf extract-mediated silver nanoparticles

This paper describes a single-step green synthesis of extracellular silver nanoparticles (AgNPs) through an in-situ bio-reduction of aqueous solution of silver nitrate using Psidium guajava L. UV–vis exhibits a characteristic surface plasmon resonance peak at around 487nm. XRD analysis showed crystalline and face-centered cubic geometry of synthesized AgNPs. TEM results revealed stable and spherical particles with a mean diameter size of ~60nm. Fourier transform infrared spectroscopy showed that the nanoparticles were capped with plant bioactive molecules. Phytosynthesized AgNPs showed broad-spectrum anti-microbial activity against Gram-positive, Gram-negative human pathogenic bacteria, and fungi. AgNPs showed prominent ability to inhibit the biofilms formed by Staphylococcus aureus, Escherichia coli and Candida albicans in a laboratory condition through crystal violet assay. The results suggest AgNPs as a promising candidate for the design of an effective antimicrobial and anti-biofilm agent in biomedical field.