Green Synthesis of Silver Nanoparticles using Randia dumetorum seed, Characterization and Antioxidant activity

Green synthesis and characterization of copper nanoparticles using Azadirachta indica leaves

The science of nanotechnology and nanoparticles is the manipulation of matter on atomic and molecular weight, the nanotechnology and nanomaterial’s refer to the particular technological goal which is precise manipulation of atom and molecules for used the fabrication process of microbial products and it is now concern to as molecular nanotechnology, it also known as the nanotechnology is science of designing, making and application of nano-structure and nanomaterials also used investigation of relationship various properties of materials with their nanometer dimensions. The exploitation of various plant materials for the biosynthesis of silver nano particles is considered a green technology. Because it does not involves any harmful chemicals. Nanotechnology field is one of the most attractive researches. The field of nanotechnology is applied to bio materials. Nanoparticles are generally considered as particles with a size up to 100 nm, that have completely new or improved properties as compared to the bulk material that they are collected based on particular characteristics such as size, distribution and morphology. Different groups of unorganized parts of the plants have been utilizing for the green synthesis of silver nanoparticles, in the present work the fresh leaves of euphorbia umbellate have been used for the synthesis of silver nanoparticles. Synthesis of AgNPs employing either microorganisms or plant extracts has emerged as an alternative approach. Silver nanoparticles is embedded with antibacterial properties because of its unique properties is considered in medical science, the main aim of work is green synthesis of silver nanoparticles using Euphorbia Umbellate leaf extract and its antibacterial activity, after the collection of sample, identification and extraction of Euphorbia Umbellate was performed the production of silver nanoparticles.

Nanotechnology deals with the synthesis of nanoparticles with controlled size, shape and dispersity of materials at the nanometer scale and their potential use for human well bein g. This leads to focus on “Green Synthesis” of nanoparticles which seems to be an easy, efficient and eco- friendly approach. In this study, the green synthesis of silver nanoparticles was carried out using root extract of Morinda pubescens as reducing agent. It was found that aqueous silver ions can be reduced by aqueous root extr act of Morinda pubescens to generate extremely stable silver nanoparticles in water. The silver nanoparticles (AgNPs) formation was confirmed by the colour change of the mixture and further confirmed by spectral analysis. UV-Visible spectrum of the aqueous medium containing silver nanoparticles showed a peak around 416.5 nm. FT -IR analysis confirmed reduction of Ag+ ions to Ag0 ions in synthesized silver nanoparticles. Further, the produced silver nanoparticles showed bactericidal effect against Staphylococcus aureus, Escherichia coli and Aspergillus niger. From this study concluded that the root extract of Morinda pubescens reduces Ag+ to Ag0 and enhances synthesis of silver nanoparticles with antimicrobial activity.

Metal nanoparticles are essential due to their unique catalytic, electrical, magnetic, and optical characteristics, as well as their prospective use in sensing, catalysis, and biological research. In recent years, researchers have focused on developing cost-effective and eco-friendly biogenic practices using the green synthesis of metal nanoparticles (AgNP). In the present study, the aqueous extracts prepared from the leaf, stem, bark, and flower of Neolamarkia cadamba were used for the synthesis of silver nanoparticles. Synthesized silver nanoparticles were characterized using UV-Visible spectroscopy, zeta potential, dynamic light scattering, scanning electron microscope (SEM), and EDAX. The current study showed absorption of synthesized AgNPs at 425, 423, 410, and 400 nm. Dynamic light scattering of AgNPs Showed size distribution of AgNPs synthesized from leaf, stem, and flower aqueous extracts ranges from 80-200 nm and AgNPs prepared from bark extract ranges from 100-700 nm. Zeta-potential of the biosynthesized AgNPs was found as a sharp peak at -23.1 mV for the leaf, -27.0 mV for the stem, -34.1 mV for the bark, and -20.2 mV for the flower. Silver nanoparticles and crude extracts of Neolamarkia cadamba showed effective antibacterial, antifungal, and antioxidant activities. Silver nanoparticles have substantial antibacterial activity against Gram-positive bacteria and also exhibit the utmost antifungal activity against Aspergillus niger. The study concludes that the green synthesis of silver nanoparticles from N. cadamba leaf, stem, bark, and flower extract is a reliable and eco-friendly technique.

Nanoparticles and nanomaterials are at the prominent edge of the rapidly developing field of nanotechnology. Recently, nanoparticle synthesis using biological resources has been found to be a new area with considerable prospects for development. Biological systems are the masters of ambient condition chemistry and are able to synthesize nanoparticles by utilizing metal salts. In the perspective of the current initiative to develop green technologies for the synthesis of nanoparticles, microorganisms are of considerable interest. Thus, the present study describes a bacterial strain—Weissella oryzae DC6—isolated from mountain ginseng, for the green and facile synthesis of silver nanoparticles. The particles were synthesized effectively without the need for any supplementary modification to maintain stability. The synthesized nanoparticles were evaluated by several instrumental techniques, comprising ultraviolet–visible spectrophotometry, field emission transmission electron microscopy, energy dispersive X-ray spectroscopy, elemental mapping, X-ray diffraction, and dynamic light scattering. In addition, the biosynthesized silver nanoparticles were explored for their antimicrobial activity against clinical pathogens including Vibrio parahaemolyticus, Bacillus cereus, Bacillus anthracis, Staphylococcus aureus, Escherichia coli, and Candida albicans. Furthermore, the potential of nanoparticles has been observed for biofilm inhibition against Staphylococcus aureus and Pseudomonas aeruginosa. Thus, the synthesis of silver nanoparticles by the strain W. oryzae DC6 may serve as a simple, green, cost-effective, consistent, and harmless method to produce antimicrobial silver nanoparticles.

Background: Appearance of antibiotic resistance has raised the demand to find alternative therapies and modified drug delivery system of medicinal plants to treat bacterial infections.
 Objective: The aim of this study is the green synthesis and characterization of silver nanoparticles by using crude extract of Crotalaria burhia and to evaluate their antibacterial potential.
 Methods: The roots and stems of plant were used to prepare the crude extract. The phytochemical analysis of different compounds in extract was performed. 1mM AgNO3 and different concentrations of plant extract were used for the green synthesis of silver nanoparticles. The particles size and zeta potential were measured by zeta sizer while surface morphology of silver nanoparticles was observed with Scanning Electron Microscope (SEM). The antibacterial activity of silver nanoparticles was performed by 96 well microdilution plate method.
 Results: The particle size and zeta potential of optimized formulation was 92 nm and -24.8 mV. The SEM analysis showed that silver nanoparticles are irregular and spherical shape. The antibacterial activity showed that MIC value of silver nanoparticles was lower for E. coli than S. aureus.
 Conclusion: Silver nanoparticles possess potent bactericidal activity against E. coli and moderate activity against S. aureus. It had been concluded that these nanoparticles can be used against multi-drug resistant bacterial infections.

Nanotechnology has become the foremost promising and rising field of analysis as a result of its applications in numerous fields. Development of consistent and greener ways for the synthesis of nanoparticles could be a dynamic step in the field of nanotechnology. To avoid the emergence of dangerous by-products, many attempts have been made in recent years to develop environment friendly methods. “Green” synthesis is a consistent, sustainable, and environment friendly method for the synthesis of an enormous range of nanoparticles. Green synthesis is seen as an important tool to reduce the harmful effects of traditional nanoparticle synthesis methods commonly used in laboratories and industries. Nanoparticles exhibit unique chemical and physical properties that are useful in various fields. Among metallic nanoparticles, silver nanoparticles have become a research hotspot due to their wide range of applications. Silver nanoparticles are important because of their exceptional chemical, physical, and biological properties. Because of these unique characteristics, silver nanoparticles have numerous applications and are used as antifungal, antiviral, and antibacterial agents. They have an excellent catalytic effect on dye degradation, are very good antioxidants, and can be used to treat various diseases and exhibit wound-healing activities. The current review complies with the database of green synthesis of silver nanoparticles using plant extracts, bacteria, and fungi, which have potential applications in fields of science, health, textiles, food packaging, agriculture, and environment. The review also highlights the application of silver nanoparticles as antimicrobial, antibacterial, antiviral, and antifungal agents. The knowledge on silver nanoparticle production conditions, properties, molecular mechanisms, and applications will be of great help for researchers to explore more applications of nanoparticles in fields that are still untouched.

The development of competent green chemistry methods for synthesis of metal nanoparticles has become a main focus of researchers. In this study we report the green synthesis of silver nanoparticles (AgNps) by reduction of silver nitrate, using leaf broth of Azadirakta indica (Neem). The plant leaf broth simultaneously acts as reducing agent as well as capping agent at 30 °C. The effect of different concentration of silver ions, percentage of leaf broth and temperature on morphology of dispersed silver nanoparticles was studied. The formation of silver nanoparticles in dispersion was monitored through the analysis of absorbance spectra by UV-Visible spectrophotometer at different stages during the process of synthesis. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis revealed that silver nanoparticles were pure and monodispersed and size was ranging from 9-56 nm. Fourier transform infrared (FTIR) analysis indicates prominent bands of absorbance, which are responsible for reducing of Ag+ ions and stabilization of obtained silver nanoparticles. Results confirmed this protocol as simple, rapid, cost effective, eco-friendly and alternative conventional physical/chemical methods.

Cost-effective, eco-friendly green synthesis of silver nanoparticles was prepared using Psidium guajava plant leaf extract. In this study the reducing potential of Psidium guajava leaf extract was investigated for the synthesis of silver nanoparticles without any external addition of reducing agents. The brown color formation was evident for the synthesis of silver nanoparticles. The synthesized silver nanoparticles were characterized by UV–Visible spectroscopy, Fourier transform-infrared spectroscopy (FTIR), particle size analyzer, X-ray diffraction (XRD) and scanning electron microscope (SEM). UV–Vis spectroscopy explained that the main peak was formed at around 419 nm, which corresponds to surface plasmon resonance of silver nanoparticles. FTIR spectroscopy elucidated the involvement of various functional groups during the synthesis of silver nanoparticles. The particle size analysis demonstrated the sizes of nanoparticles are 62 nm. The morphology of silver nanoparticles was analyzed using scanning electron microscope. Antibacterial assay of silver nanoparticles showed potent antibacterial properties.

The extract of Carpesium cernuum whole plant was successfully used as a green factory for the synthesis of silver nanoparticles in a one-step, one-pot process. The extract efficiently reduced silver ions to spherical silver nanoparticles. The size was measured as 13.0 ± 0.2nm from high resolution transmission electron microscopic images. The reaction yield was determined to be 99.6% using inductively coupled plasma optical emission spectroscopy. The silver nanoparticles were highly stable for 28days at ambient temperature without forming agglomeration or aggregation of nanoparticles. Dose-dependent antioxidant activity of the silver nanoparticles was observed in terms of the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl radicals. The silver nanoparticles also exerted cytotoxicity on Mus musculus skin melanoma cells (B16F10) and human lung cancer cells (A549) in a dose-dependent manner. Specifically, the cytotoxicity of the silver nanoparticles on A549 cells was closely associated with apoptotic cell death. Cellular uptake of the silver was evaluated via inductively coupled plasma mass spectrometry, and a higher percentage of silver was taken up by A549 cells (22.6%) than by B16F10 cells (17.3%). This result indicated that higher cellular uptake of silver nanoparticles resulted in higher cytotoxicity on A549 cells. Therefore, plant extracts are capable of being valuable natural sources for the green synthesis of silver nanoparticles that exhibit potent biological activities for pharmaceutical and biomedical applications in future nanomedicine.

White biotechnology can be regarded as applied biocatalysis, with enzymes and microorganisms, aiming at industrial production of bulk and fine chemicals to food and animal feed additives. In its turn biocatalysis has many attractive features in the context of greenchemistry: mild reaction conditions (physiological pH and temperature); environmentally compatible catalysts and solvent (often water) combined with high activities; and chemo-, regio-, and stereoselectivities in multifunctional molecules. This affords processes which are shorter, generate less waste, and are, therefore, both environmentally and economically more attractive than conventional routes. This special issue includes aspects involving the use of white biotechnology (enzymes, microorganisms, and plant tissues) within the green chemistry concept, concerning the use of alternative solvents (supercritical fluids, pressurized gases, ionic liquids, and micellar systems) and energies (microwaves and ultrasound); sustainable approaches for production of fine and bulk chemicals (aromas, polymers, pharmaceuticals, and enzymes); use of renewable resources or agroindustrial residues; biocatalysts recycling; and waste minimization. This special issue contains six papers, where three are related to green synthesis of nanoparticles and one paper covers biological pretreatment for enzymatic hydrolysis and bioethanol production. Two papers regard the use of alternative reaction systems. In the first paper entitled “Green synthesis of silver nanoparticles using Pinus eldarica bark extract,” S. Iravani and B. Zolfaghari present the optimization of the biosynthesis production of silver nanoparticles through the evaluation of Pinus eldarica bark extract quantity, substrate concentration, temperature, and pH on the formation of such material. The preparation of nanostructured silver particles using P. eldarica bark extract provides an environmentally friendly option, as compared to currently available chemical and/or physical methods. The second paper, “Green and rapid synthesis of anticancerous silver nanoparticles by Saccharomyces boulardii and insight into mechanism of nanoparticle synthesis,” by A. Kaler et al. describes an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) by cell free extract (CFE) of Saccharomyces boulardii. In addition to the optimization of relevant synthesis parameters as culture age, cell mass concentration, temperature, and reaction time, the paper presents particles characterization by UV-Visible spectroscopy, EDX (energy dispersive X-Rays) analysis, transmission electron microscopy, and zeta potential, as well as the elucidation of proteins/peptides role in nanoparticles formation and stability and their anticancer activity. The method therein described a method that does not require tedious downstream processing and it may be scaled up to develop a viable technology for the Ag-nanoparticle synthesis. In the third paper, “Biosynthesis, antimicrobial and cytotoxic effect of silver nanoparticles using a novel Nocardiopsis sp. MBRC-1,” P. Manivasagan et al. present another green approach for biosynthesis of nanoparticles using the culture supernatant of Nocardiopsis sp. MBRC-1 to achieve the reduction of silver ions from a silver nitrate solution. The obtained nanoparticles were characterized by UV-visible, TEM, FE-SEM, EDX, FTIR, and XRD spectroscopy. The prepared silver nanoparticles exhibited strong antimicrobial activity against bacteria and fungi. Cytotoxicity of biosynthesized AgNPs against in vitro human cervical cancer cell line (HeLa) showed a dose-response activity. In the fourth paper, “Biological pretreatment of rubberwood with Ceriporiopsis subvermispora for Enzymatic hydrolysis and bioethanol production,” F. Nazarpour et al. investigate a novel feedstock for enzymatic hydrolysis and bioethanol production using biological pretreatment: rubberwood (Hevea brasiliensis). To improve ethanol production, rubberwood was pretreated with white rot fungus Ceriporiopsis subvermispora to increase fermentation efficiency. The fungal pretreatment provides a cost-effective method for reducing the recalcitrance of rubberwood with high selectivity of lignin degradation rate and minimal cellulose loss for enzymatic hydrolysis and bioethanol production. In the fifth paper, the research of G. D. Yadav and S. Devendran entitled “Microwave assisted enzymatic kinetic resolution of (±)-1-phenyl-2-propyn-1-ol in non-aqueous media,” proposes a kinetic resolution of 1-phenyl-2-propyn-1-ol, an important chiral synthon, through esterification with acyl acetate. The authors investigate synergism between microwave irradiation and enzyme catalysis. The lipase (Novozym 435) catalyzed kinetic resolution under microwave irradiation. The maximum conversion of 48.78% was obtained in 2 h using 10 mg enzyme loading with equimolar concentration of alcohol and ester at 60°C under microwave irradiation. From the progress curve analysis, it was found that reaction followed the ping-pong bi-bi mechanism with dead end inhibition of alcohol. Beside the previous papers herein described, the preparation of chiral secondary alcohols using lipase catalyzed kinetic resolution is mild and clean as compared to chemical process. In the seventh paper entitled “Demonstration of redox potential of Metschnikowia koreensis for stereoinversion of secondary alcohols/1,2-diols,” by V. S. Meena et al. reports the Metschnikowia koreensis-catalyzed one-pot deracemization of secondary alcohols/1,2-diols and their derivatives with in vivo cofactor regeneration. This ecofriendly method afforded the product in high yield (88%) and excellent optical purity (>98% ee), minimizing the requirement of multistep reaction and expensive cofactor. Bernardo Dias Ribeiro Isabel Marrucho Luciana Goncalves Maria Alice Z. Coelho

The green synthesis of nanoparticles is an important branch and a relatively new emerging field in nanotechnology which is easy, environmentally friendly, cost effective, and economically efficient in comparison with the chemical and physical methods. In the present work, for the first time, green synthesis of silver nanoparticles (AgNPs) was carried out by using fructose solution as a reducing agent at room temperature. The silver nanoparticles were characterized by UV-Vis, FTIR, XRD, and TEM analysis. The UV-Vis spectral studies confirmed the surface plasmon resonance of the green synthesized silver nanoparticles. The role of different functional groups in formation of the AgNps was shown by FTIR. X-ray diffraction results confirmed the formation of the the AgNPs and TEM results indicated that the average particle size of the silver nanoparticles was 13.24±8.591 nm.

Background: Nanotechnology, particularly the use of silver nanoparticles (AgNPs), has gained significant interest due to its wide-ranging applications in healthcare, industry, and environmental sectors. However, traditional chemical methods for silver nanoparticles (AgNPs) synthesis raise concerns regarding their environmental and biocompatibility. Green synthesis approaches, such as using plant extracts, offer an eco-friendly alternative. Aim: This study investigates the synthesis of silver nanoparticles (AgNPs) using Lactuca runcinata DC extract to evaluate their antimicrobial properties, supported by an in-silico molecular docking study. Methods: Silver nanoparticles were synthesized by mixing an aqueous extract of L. runcinata DC with silver nitrate (AgNO₃) solution. The synthesis process was monitored visually and confirmed using UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Fourier-Transform Infrared Spectroscopy (FTIR). These techniques helped verify the formation, size, morphology, and structural integrity of the nanoparticles. Results: Characterization revealed that the synthesized silver nanoparticles (AgNPs), were spherical and crystalline. UV-Vis spectra showed a distinct peak, confirming the presence of silver nanoparticles. SEM images supported their spherical shape, while XRD confirmed their crystalline structure. FTIR analysis indicated that plant phytochemicals stabilized the nanoparticles. The silver nanoparticles (AgNPs), exhibited significant antimicrobial activity, especially against Escherichia coli. Molecular docking studies showed strong interactions between phytochemicals from the extract and Cyclin-dependent kinase 8 (CDK8), suggesting potential for antimicrobial and anticancer applications. Conclusion: The green synthesis of silver nanoparticles (AgNPs), using L. runcinata DC extract, produced nanoparticles with promising antimicrobial activities. Major Findings: Silver nanoparticles synthesized from L. runcinata DC extract were spherical, crystalline, and phytochemically stabilized, exhibiting strong antimicrobial activity against E. coli and notable CDK8 binding, indicating potential antimicrobial and anticancer properties.

Green synthesis is the synthesis of nanoparticles using biological systems and is greatly beneficial because of its non-toxicity and eco-friendly behaviour. This study focuses on the green synthesis of silver nanoparticles using Aloe vera gel extract and Abelmoschus esculentus extract and its characterization and antibacterial activity. The synthesized nanoparticles were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and UV- Vis Spectroscopy. The bio-reduction of aqueous Ag+ ions by these extracts were identified by their colour change. The change in colour indicates the formation of AgNPs (Silver Nanoparticles). Silver nanoparticles showed maximum absorbance at 250nm in both Aloe vera gel extract and Abelmoschus esculentus. A peak obtained at this point confirmed the presence of AgNPs. Moreover, the synthesized silver nanoparticle showed potential antibacterial activity against the selective strains of bacteria such as Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes which were studied using the well-diffusion method. This study gives a scope for its potential applications in biomedical field.

Nanoparticles are molecules in the range of 1 nm to 100 nm and they can be synthesized by physical, chemical and biological methods. Green synthesis involves the production of nanoparticles from bacteria, fungi, algae, plants and plant extracts. Plant extracts with their chemical constituents can capture the target metals from their salt solution and transform the metal particles into nanoparticles with the cellular catalysts. The present study focuses on the green synthesis of silver nanoparticles using the liquid endosperm of coconut, the coconut water (Cocos nucifera), Liquid endosperm of palm fruit (Borassus flabellifer) and coconut Toddy as the reducing agent. The bio-reduction of aqueous silver ions by coconut water is identified by its colour change. During the synthesis of silver nanoparticles, the colour of the solution changed from milky white to brown. The characterization of synthesized AgNPs (Silver Nanoparticles) was done by Fourier Transform Infrared Spectroscopy and UV-Vis Spectroscopy. The peaks obtained at 250 and 350 nm confirmed the presence of synthesized Silver Nanoparticles. The antibacterial activity of the synthesized nanoparticles was studied on Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes using disc diffusion method. The recent approach of green synthesis is quite impressive due to its eco- friendly, economical, feasible and non- toxic nature.