Biosynthesis Of AgNPs Research Articles

Biosynthesis and Characterization of Silver Nanoparticles Coated with Metabolites Extracted from Clerodendron phlomoides with Its Biochemical Studies in Liver Tissue

Silver nanoparticles (AgNPs) have been used as a potential nanomaterial-based drug delivery vehicle for liver cancer treatment, as it induces cell death and produces cytotoxicity against cancerous cells at a low concentration. The biosynthesis of green metallic nanoparticles uses secondary metabolites in plant extracts instead of toxic chemicals for a reduction-oxidation (redox) reaction. The biosynthesis of AgNPs with the aqueous extract of Clerodendron phlomoides was performed in this study. The phytochemical analysis of C. phlomoides extract using gas chromatography-mass spectrometry (GC-MS) confirmed the presence of redox metabolites. The peak at 489 nm in UV-visible spectra confirmed the formation of bioactive AgNPs reduced from silver nitrate solution, whereas the Fourier-transform infrared (FTIR) spectra indicated the bioactive molecules of plant extracts that are responsible for the formation. Scanning electron microscope (SEM) micrograph revealed the formation of spherical and ovoid structures of AgNPs, whereas transmission electron microscope (TEM) micrograph confirmed the size of AgNPs, which varies from 25 nm to 100 nm. X-ray diffraction (XRD) spectra showed the crystalline nature of AgNPs, and the size of crystallite was 4 nm, while dynamic light scattering (DLS) analysis confirmed the average particle size of AgNPs to be around 125 nm. In vivo studies showed that bioactive AgNPs have a significant anticancer potential against liver cancer, whereas biochemical studies of rats’ liver tissue samples confirmed that bioactive AgNPs produced a potential hepatoprotective effect against diethylnitrosamine-induced liver cancer.

Preferential role of distinct phytochemicals in biosynthesis and antibacterial activity of silver nanoparticles

Biosynthesis of silver nanoparticles (AgNPs) by plant extracts and its antibacterial utilization has attracted great attention due to the spontaneous reducing and capping capacities of phytochemicals. However, the preferential role and mechanisms of the functional phytochemicals from different plants on AgNPs synthesis, and its catalytic and antibacterial performance remain largely unknown. This study used three widespread arbor species, including Eriobotrya japonica (EJ), Cupressus funebris (CF) and Populus (PL), as the precursors and their leaf extracts as reducing and stabilizing agents for the biosynthesis of AgNPs. A total of 18 phytochemicals in leaf extracts were identified by ultra-high liquid-phase mass spectrometer. For EJ extracts, most kinds of flavonoids participated in the generation of AgNPs by a reduced content of 5∼10%, while for CF extracts, about 15∼40% of the polyphenols were consumed to reduce Ag+ to Ag0. Notably, the more stable and homogeneous spherical AgNPs with smaller size (≈38 nm) and high catalytic capacity on Methylene blue were obtained from EJ extracts rather than CF extracts, and no AgNPs were synthesized from PL extracts, indicating that flavonoids are superior than polyphenols to act as reducer and stabilizer in AgNPs biosynthesis. The antibacterial activities against Gram-positive (Staphylococcus aureus and Bacillus mycoides) and Gram-negative bacteria (Pseudomonas putida and Escherichia coli) were higher in EJ-AgNPs than that in CF-AgNPs, which confirmed the synergistic antibacterial effects of flavonoids combined with AgNPs in EJ-AgNPs. This study provides a significant reference on the biosynthesis of AgNPs with efficient antibacterial utilization underlying effect of abundant flavonoids in plant extracts.

Evaluation of the Synergistic Effect of Azadirachta indica-based Silver Nanoparticles in Combination with Antibiotics and Hypoglycemic Drugs: In vitro Antimicrobial and In vivo Antidiabetic Activities

This study was conducted to evaluate the synergistic effects of the mixtures of green silver nanoparticles (AgNPs) with ampicillin and metformin separately in obviating the global threats of antimicrobial resistance and diabetes mellitus. AgNPs was synthesized using Azadirachta indica aqueous leaf extract at varying extract concentration and incubation time. The synthesis of AgNPs in aqueous solution was confirmed by the visual color change and by using a UV-Vis spectrophotometer. The biosynthesized AgNPs was further characterized using Scanning Electron Microscope (SEM) analysis. The experimental results revealed that the biosynthesized AgNPs were polydispersed, smaller in size and aggregated. The mean diameter of the formed AgNPs was 50 nm as evident from the SEM analysis. Additionally, the mixtures of AgNPs with ampicillin and metformin exhibited synergistic in vitro antimicrobial and in vivo antidiabetic effects i.e., being more efficacious than AgNPs, ampicillin and metformin alone.
 J. of Sci. and Tech. Res. 4(1): 91-100, 2022

Green synthesized metal silver nano particles for fabric coating and its applications

The safest and the most environmental friendly processes for synthesizing nanoparticles is green synthesis. Plant sources can be used as reducing agents in place of hazardous chemicals and thus prevents causing environmental toxicity. Silver NPs takes the most fascinating position because of its unique antimicrobial properties. The bark extract of Barringtonia acutangula was used in the current study to biosynthesize silver nanoparticles (AgNPs), which were then coated on pure cotton fabric using the dip coat method. Initially, the synthesised AgNPs was visualised by change in colour. Additionally, FT-IR, UV–Visible spectroscopy, SEM, and TEM were used to study the morphology of the nanoparticles, their average size, and the presence of elemental silver. XRD results confirmed that the green synthesized AgNPs have an average particle size and are face-centered cubic crystalline in nature. In vitro antimicrobial effect of AgNPs coated cotton cloth was tested against both Gram-positive and Gram-negative bacterial strains. The findings demonstrate that biosynthesized AgNPs have potent antibacterial properties. It was proven that the bactericidal effect was very effective. The coated fabric has potential uses as a bed liner, a wound dressing, and as medical bandages. The coated fabric is also suggested for cleaning domestic spaces and for sanitizing food- and medical-related equipment. Furthermore,The ingredients used in the preparation are also affordable, non-toxic, and widely accessible..

Biosynthesis of Silver Nanoparticles and Their Applications

Recent developments in nanotechnology and nanoscience have improved methods for treating, preventing, and diagnosing a wide range of illnesses in many parts of living beings. Silver nanoparticles (Ag NPs) are among the most significant and intriguing metallic nanoparticles employed in several biological applications. To create Ag NPs, biomolecules from diverse microbial species and plant components have been researched as possible agents. Due to their physical orientation characteristics, and small size, these Ag NPs are widely employed and are said to have an impact on the performance of any other material that comes into touch with them. In addition, straightforward biological, physical, and chemical methods may be used to create Ag NPs. Due to their enhanced responsiveness to environmentally friendly technology for quantifiable synthesis, several developed nations have seen significant growth in the biosynthesis of Ag NPs. The biological method, however, is the approach to preparation that is most in demand since it is quicker, safer, less expensive, and more environmentally friendly than other techniques. In addition, the importance of Ag NPs is extensively examined in light of their numerous bioapplications, including those for antifungal, anti-inflammatory, antibacterial, Antiviral activity, Catalytic Activity, and anticancer medicines

Green Synthesis and Characterization of Novel Silver Nanoparticles Using Achillea maritima subsp. maritima Aqueous Extract: Antioxidant and Antidiabetic Potential and Effect on Virulence Mechanisms of Bacterial and Fungal Pathogens

Novel silver nanoparticles were synthesized based on a simple and non-toxic method by applying the green synthesis technique, using, for the first time, the aqueous extract of an extremophile plant belonging to the Achillea maritima subsp. maritima species. AgNP characterization was performed via UV-Visible, front-face fluorescence spectroscopy, and FTIR and XRD analyses. AgNP formation was immediately confirmed by a color change from yellow to brown and by a surface plasmon resonance peak using UV-Vis spectroscopy at 420 nm. The biosynthesized AgNPs were spherical in shape with a size ranging from approximatively 14.13 to 21.26 nm. The presented silver nanoparticles exhibited strong antioxidant activity following a DPPH assay compared to ascorbic acid, with IC50 values of about 0.089 µg/mL and 22.54 µg/mL, respectively. The AgNPs showed higher antidiabetic capacities than acarbose, by inhibiting both alpha amylase and alpha glucosidase. The silver nanoparticles could affect various bacterial mechanisms of virulence, such as EPS production, biofilm formation and DNA damage. The silver nanoparticles showed no lysozyme activity on the cell walls of Gram-positive bacteria. The AgNPs also had a strong inhibitory effect on the Candida albicans virulence factor (extracellular enzymes, biofilm formation). The microscopic observation showed abnormal morphogenesis and agglomeration of Candida albicans exposed to AgNPs. The AgNPs showed no cytotoxic effect on human cells in an MTT assay. The use of novel silver nanoparticles is encouraged in the formulation of natural antimicrobial and antidiabetic agents.

Differential Antimicrobial Effect of Three-Sized Biogenic Silver Nanoparticles as Broad-Spectrum Antibacterial Agents against Plant Pathogens.

Massive fruit losses are caused by microbial pathogens of unknown identities. Therefore, ecofriendly biocontrol measures are well sought after, and biogenic silver nanoparticles are plausible candidates. Here we investigate the antimicrobial effect of three different sized AgNPs samples on those pathogens. Identities of three local pathogenic bacteria were investigated using molecular methods. Three different-sized samples of silver nanoparticles were bio-synthesized in the external solution of a cyanobacterial culture, characterized, and used in antimicrobial bioassay. The pathogens were identified as Erwinia pyrifoliae, Staphylococcus warneri, and Xanthomonas citri. UV-vis. and FTIR spectroscopy confirmed the biosynthesis of AgNPs. and their three different sizes were confirmed using Scanning electron microscopy. Growth of bacterial pathogens was inhibited by all three samples of AgNPs, but the largest inhibition zone was for the smallest sized AgNPs against Staphylococcus warneri (1.7 cm). The identity of the pathogens infecting different local fruits is reported for the first time. They belong to different bacterial lineages. The fact that biogenic AAgNPs were effective against all of them shows their broad-spectrum of antibacterial effect. Customized biosynthesis was successful in yielding different-sized AgNPs. The smaller the AgNPs, the stronger the antimicrobial impact. Local bacterial species infecting fruits are diverse. Customized biogenic AgNPs are effective broad-spectrum biocontrol agents against bacterial pathogens of local fruits and thereby help maintain food security and environmental sustainability.

Green Synthesis of Silver Nanoparticles using Egyptian Date Palm (Phoenix dactylifera L.) Seeds and Their Antibacterial Activity Assessment

A simple, cost-effective and eco-friendly synthesis technique of silver nanoparticles (AgNPs) using the aqueous extracts of Egyptian date palm (Phoenix dactylifera L.) seeds and their antibacterial activity assessment have been conducted. Theaqueous extract was used as reducing and stabilizer agents in the synthesis of AgNPs. Characterization of AgNPs was done using different methods including ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR), field emission-scanning electron microscope (FE-SEM), and X-ray diffraction (XRD). UV-Vis spectrum of the aqueous medium containing AgNPs showed an absorption peak at around 432 nm. FTIR spectra had shown that the biomolecules were responsible for the reduction and capping agents of AgNPs. XRD study showed the particles to be crystalline with a face-centered cubic (fcc) structure. The AgNPs exhibited significant anti-bacterial activity against Bacillus subtilis, Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus. Overall, these findings suggest that biosynthesized AgNPs may be used as a potential therapeutic formulation against bacterial infections.

Biosynthesis and Characterization of Silver Nanoparticles Produced by Parachlorella kessleri and Cyclotella spp., and the Evaluation of Their Antibacterial Activity.

Green synthesis is one of the fastest and best ways for ecofriendly nanoparticle synthesis. This study aims to investigate the use of the green microalgae Parachlorella kesseleri and Cyclotella spp. for the biological synthesis of silver nanoparticles (AgNPs). This work focuses on optimizing various parameters necessary for the production and stability of AgNPs. The nanoparticle formation was confirmed by UV-Visible analysis, which revealed the surface plasmon resonance band at 420 nm. The characterization of the AgNPs was performed using UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The antimicrobial properties of these bioactive AgNPs were also tested, showing excellent antibacterial activity against six bacterial strains, Escherichia coli, multidrug-resistant Escherichia coli, Bacillus clausii, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhi. The biosynthesis of AgNPs from living cultures of microalgae has remarkable antibacterial properties. Other studies are underway in our laboratory to clarify the mechanism of the biosynthesis of these nanoparticles, and their action on bacteria.

Antioxidant Activities of Photoinduced Phycogenic Silver Nanoparticles and Their Potential Applications.

While various methods exist for synthesizing silver nanoparticles (AgNPs), green synthesis has emerged as a promising approach due to its affordability, sustainability, and suitability for biomedical purposes. However, green synthesis is time-consuming, necessitating the development of efficient and cost-effective techniques to minimize reaction time. Consequently, researchers have turned their attention to photo-driven processes. In this study, we present the photoinduced bioreduction of silver nitrate (AgNO3) to AgNPs using an aqueous extract of Ulva lactuca, an edible green seaweed. The phytochemicals found in the seaweed functioned as both reducing and capping agents, while light served as a catalyst for biosynthesis. We explored the effects of different light intensities and wavelengths, the initial pH of the reaction mixture, and the exposure time on the biosynthesis of AgNPs. Confirmation of AgNP formation was achieved through the observation of a surface plasmon resonance band at 428 nm using an ultraviolet-visible (UV-vis) spectrophotometer. Fourier transform infrared spectroscopy (FTIR) revealed the presence of algae-derived phytochemicals bound to the outer surface of the synthesized AgNPs. Additionally, high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) images demonstrated that the NPs possessed a nearly spherical shape, ranging in size from 5 nm to 40 nm. The crystalline nature of the NPs was confirmed by selected area electron diffraction (SAED) and X-ray diffraction (XRD), with Bragg's diffraction pattern revealing peaks at 2θ = 38°, 44°, 64°, and 77°, corresponding to the planes of silver 111, 200, 220, and 311 in the face-centered cubic crystal lattice of metallic silver. Energy-dispersive X-ray spectroscopy (EDX) results exhibited a prominent peak at 3 keV, indicating an Ag elemental configuration. The highly negative zeta potential values provided further confirmation of the stability of AgNPs. Moreover, the reduction kinetics observed via UV-vis spectrophotometry demonstrated superior photocatalytic activity in the degradation of hazardous pollutant dyes, such as rhodamine B, methylene orange, Congo red, acridine orange, and Coomassie brilliant blue G-250. Consequently, our biosynthesized AgNPs hold great potential for various biomedical redox reaction applications.

Evaluation of Antibacterial, Antioxidant and Seed Germination Potential of Biosynthesized Silver Nanoparticles from Bark Extract of Ailanthus excelsa Roxb.

Nanotechnology, an emerging scientific domain promises potential applications in varied sectors. Currently, research in nanotechnology focuses on the optimization of nanoparticle synthesis. Green synthesis of nanoparticles is an economic and non-toxic alternative to conventional methods. In the present study, aqueous bark extract of Ailanthus excelsa Roxb. was used for the biosynthesis of silver nanoparticles (AgNPs). UV-Visible Spectroscopy confirmed the presence of AgNPs with an absorption Surface Plasmon peak at 450nm. Biosynthesized AgNPs and bark extract were investigated using Fourier Transform Infrared Spectroscopy (FTIR) for determining the functional groups in phytochemicals that act as reducing and capping agents in the synthesis process. High-Resolution Transmission Electron Microscopy (HRTEM) analysis denotes that AgNPs were predominantly spherical, with an average size of 18.84 ± 2.28nm. The bark extract was evaluated qualitatively by preliminary phytochemical screening. Antioxidant potential of biosynthesized AgNPs and bark extract were analyzed using the DPPH method in which biosynthesized AgNPs showed significant free radical scavenging potential. Antibacterial properties of biosynthesized AgNPs were analysed against Escherichia coli and Staphylococcus aureus. Biosynthesized AgNPs and bark extract were also checked for Germination Percentage, Germination Speed Index and Seedling Vigor Index on Wheat (Triticum aestivum L.) and Moong (Vigna radiata (L.) R. Wilczek) seeds. The present study infers that Ailanthus excelsa Roxb. act as a potential source of green synthesis of AgNPs and may help to build a resilient system for its commercial applications in various fields.

Synergistic Effects of AgNPs and Biochar: A Potential Combination for Combating Lung Cancer and Pathogenic Bacteria.

The synthesis of reliable biological nanomaterials is a crucial area of study in nanotechnology. In this study, Emericella dentata was employed for the biosynthesis of AgNPs, which were then combined with synthesized biochar, a porous structure created through biomass pyrolysis. The synergistic effects of AgNPs and biochar were evaluated through the assessment of pro-inflammatory cytokines, anti-apoptotic gene expression, and antibacterial activity. Solid biosynthesized AgNPs were evaluated by XRD and SEM, with SEM images revealing that most of the AgNPs ranged from 10 to 80 nm, with over 70% being less than 40 nm. FTIR analysis indicated the presence of stabilizing and reducing functional groups in the AgNPs. The nanoemulsion's zeta potential, hydrodynamic diameter, and particle distribution index were found to be -19.6 mV, 37.62 nm, and 0.231, respectively. Biochar, on the other hand, did not have any antibacterial effects on the tested bacterial species. However, when combined with AgNPs, its antibacterial efficacy against all bacterial species was significantly enhanced. Furthermore, the combined material significantly reduced the expression of anti-apoptotic genes and pro-inflammatory cytokines compared to individual treatments. This study suggests that low-dose AgNPs coupled with biochar could be a more effective method to combat lung cancer epithelial cells and pathogenic bacteria compared to either substance alone.

Photocatalytic and biological properties of silver nanoparticles synthesized using Callistemon lanceolatus leaf extract

Silver nanoparticles (AgNPs) have been extensively explored due to their diverse applications in catalysis, medicine, drug delivery, etc. Physical and chemical methods of synthesizing AgNPs pose a threat to the environment due to the use of toxic and non-biodegradable substances. Green synthesis of AgNPs due to its eco-friendly nature is considered a novel approach as it can be easily scaled up and avoid the use of toxic chemicals. The aqueous extract of leaves from Callistemon lanceolatus was used in the present study for the biosynthesis of AgNPs using the Box-Behnken design (BBD) of response surface methodology (RSM). The study involves the determination of antioxidant, antibacterial, and α-amylase inhibitory activities of biosynthesized AgNPs. In addition, the photocatalytic activity of the synthesized AgNPs was assessed through the degradation of methylene blue dye. The AgNPs showed a characteristic plasmon resonance absorption band around 424 nm. Furthermore, biosynthesized AgNPs were face-centered cubic (fcc) with an average diameter of 41.93 nm as determined by XRD and TEM analysis respectively. The chemical nature of biogenic AgNPs was ascertained using energy-dispersive X-ray (EDX) analysis. Similarly, biosynthesized AgNPs were also characterized using FTIR, SEM, and DLS analysis. The AgNPs showed potential DPPH radical scavenging (IC50 of 40.86 ± 1.8 µg/mL) and α-amylase inhibitory (85.3 % at 100 µg/mL) activities. They also possessed appreciable antibacterial activity with MIC and MBC values ranging from 40 to 80 µg/mL and 60–150 µg/mL respectively. The photocatalytic degradation of methylene blue dye by AgNPs showed a rate constant of 0.009 min−1. Also, AgNPs were effective in degrading the MB dye up to 91 % in 300 min with a concentration of 0.1 mg/mL. Additionally, the reusability of AgNPs as nano-catalyst showed a small decrease in their photo-catalytic activity after every consecutive cycle up to five cycles. It may be concluded that AgNPs produced from C. lanceolatus leaf extract may have biomedical uses and applications in the purification of water contaminated with organic dyes.

Green synthesis of Kickxia elatine-induced silver nanoparticles and their role as anti-acetylcholinesterase in the treatment of Alzheimer’s disease

Abstract The synthesis of silver nanoparticles (AgNPs) by the green method is favored as compared to chemical synthesis due to their appreciable properties of less toxicity and simple synthesis. The current study designed the biosynthesis of AgNPs in one step by using the plant Kickxia elatine (KE) extract and then investigated its inhibiting activity against rat’s brain acetylcholinesterase (AChE) ex vivo. Ultraviolet spectrum at 416 nm confirmed the formation of AgNPs. X-ray diffractometer calculated size was reported to be 42.47 nm. The SEM analysis confirmed spherical-shaped AgNPs. FT-IR suggested that the phytochemical groups present in the KE extract and their nanoparticles (NPs) are responsible for the biosynthesized of NPs. EDX analysis presented that Ag was the chief element with 61.67%. Both KE extract and AgNPs showed significant anti-AChE activity at 175 µg·mL−1. Statistical analysis showed that both KE and AgNPs exhibited non-competitive type inhibition against AChE, i.e. V max decreased (34.17–68.64% and 22.29–62.10%), while K m values remained constant. It is concluded that KE and AgNPs can be considered an inhibitor of rats’ brain AChE. Furthermore, the synthesis of AgNP-based drugs can be used as a cheaper and alternative option against diseases such as Alzheimer’s disease.

The efficacy of biosynthesized silver nanoparticles against Pseudomonas aeruginosa isolates from cystic fibrosis patients

The high antibiotic resistance of Pseudomonas aeruginosa (PA) makes it critical to develop alternative antimicrobial agents that are effective and affordable. One of the many applications of silver nanoparticles (Ag NPs) is their use as an antimicrobial agent against bacteria resistant to common antibiotics. The key purpose of this research was to assess the antibacterial and antibiofilm effectiveness of biosynthesized Ag NPs against six biofilm-forming clinically isolated strains of PA and one reference strain (ATCC 27853). Ag NPs were biosynthesized using a seed extract of Peganum harmala as a reducing agent. Ag NPs were characterized by Ultraviolet–visible (UV–Vis) spectroscopy and scanning transmission electron microscopy (STEM). The effect of Ag NPs on biofilm formation and eradication was examined through micro-titer plate assays, and the minimal inhibitory (MIC) and minimum bactericidal (MBC) concentrations determined. In addition, real-time polymerase chain reactions (RT-PCR) were performed to examine the effects of Ag NPs on the expression of seven PA biofilm-encoding genes (LasR, LasI, LssB, rhIR, rhII, pqsA and pqsR). The biosynthesized Ag NPs were spherically-shaped with a mean diameter of 11 nm. The MIC for each PA strain was 15.6 µg/ml, while the MBC was 31.25 µg/ml. All PA strains exposed to Ag NPs at sub-inhibitory concentrations (0.22–7.5 µg/ml) showed significant inhibitory effects on growth and biofilm formation. Biomass and biofilm metabolism were reduced dependent on Ag NP concentration. The expression of the quorum-sensing genes of all strains were significantly reduced at an Ag NP concentration of 7.5 µg/ml. The results demonstrate the extensive in-vitro antibacterial and antibiofilm performance of Ag NPs and their potential in the treatment of PA infection. It is recommended that future studies examine the possible synergy between Ag NPs and antibiotics.

Complexation of turmeric and curcumin mediated silver nanoparticles with human serum albumin: Further investigation into the protein-corona formation, anti-bacterial effects and cell cytotoxicity studies.

Biosynthesized noble metal nanoparticles have been of recent interest due to their broad implications in the future biomedicinal field. We have synthesized silver nanoparticle using turmeric-extract and its major component curcumin as reducing and stabilizing agents. Further, we have investigated the protein-NPs interaction focusing the inspection of the role of biosynthesized AgNPs on any conformational changes of the protein, binding and thermodynamic parameters using spectroscopic techniques. Fluorescence quenching studies revealed that both CUR-AgNPs and TUR-AgNPs have moderate binding affinities (∼104 M-1) towards human serum albumin (HSA) and static quenching mechanism was involved in the binding. Estimated thermodynamic parameters indicate the involvement of hydrophobic forces in the binding processes. The surface charge potential of the biosynthesized AgNPs became more negative upon complexation with HSA as observed from Zeta potential measurements. Antibacterial efficacies of the biosynthesized AgNPs were evaluated against Escherichia coli (gram-negative) and Enterococcus faecalis (gram-positive) bacterial strains. The AgNPs were found to destroy the cancer (HeLa) cell lines in vitro. The overall findings of our study successfully outline the detailed insight of the protein corona formation by biocompatible AgNPs and their biological applications concerning the future scope in the biomedicinal field.

Potential of Biosynthesized Silver and Zinc Oxide Nanoparticles from Carissa opaca Extracts for Antimicrobial Activity and Wastewater Treatment

The present study focus on biosynthesis of stable silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnO NPs) from the leaf and stem extract of a therapeutic plant Carissa opaca. The visual observation, Fourier Transformed Infrared Spectroscopy (FTIR), Inductively Coupled Plasma analysis (ICP), High Resolution Transmission Electron Microscopy (HRTEM), and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) were used to characterize and confirm the synthesized AgNPs and ZnO NPs. Afterwards; the synthesized nanoparticles were used to analyze their antimicrobial activity via in-vitro disk diffusion method against Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Aspergillus niger, and Candida albican. Both the nanoparticles showed maximum zone of inhibition against Pseudomonas aeruginosa (bacterial strain), whereas in the case of fungi, higher zone of inhibition was observed using ZnONPs against Candida albican and AgNPs against Aspergillus niger. The biosynthesized AgNPs was also used for degradation of methylene blue under visible-light irradiation and found dye removal efficiency of. 97.4% within 1 h.

An Eco-Friendly Synthesis of Silver Nanoparticles Using Extract of Capsicum chinense Jacq. as A Bio-reducing Agent

Silver nanoparticles (AgNPs) have become popular due to their unique properties that can be used as biosensors, composite fibers, semiconductor materials, and other medical applications. Green synthesis of AgNPs using natural reagents from plant extract offers advantages as an efficient and environmentally friendly technique by which the compounds from the extract perform as bio-reductor for silver ions and the capping agent for stabilizing the AgNPs. Therefore, the purpose of the study was to conduct the synthesis of AgNPs by utilizing an extract of Capsicum chinensie Jacq as the bioreductor. The effect of extract concentrations, duration of exposure to sunlight, and temperatures on AgNPs formation was studied to obtain the optimum synthesis condition. The biosynthesized AgNPs characteristics were analyzed using UV-Vis Spectrophotometry, FTIR, SEM, X-Ray Diffraction, and PSA. The results showed that the higher extract concentration produced smaller AgNPs. The synthesis under sunlight exposure showed more product of AgNPs compared to heating on a hot plate. The optimum conditions of biosynthesis of AgNPs were attained at the volume ratio of extract (20%) and AgNO3 (1mM) of 1:1 and duration of sunlight exposure of 90 min, resulting in AgNPs characterized with maximum wavelength 422 nm and average particle sizes of 67.94 nm.

Green synthesis of silver nanoparticles mediated Diospyros kaki L. (Persimmon): determination of chemical composition and evaluation of their antimicrobials and anticancer activities.

The eco-friendly synthesis of metallic nanoparticles (MNPs) using biological materials is an encouraging and innovativeness approach to nanotechnology. Among other synthesizing methods, biological methods are chosen because of their high efficiency and purity in many aspects. In this work, using the aqueous extract obtained from the green leaves of the D. kaki L. (DK); silver nanoparticles were synthesized in a short time and simply with an eco-friendly approach. The properties of the synthesized silver nanoparticles (AgNPs) were characterized using various techniques and measurements. In the characterization data of AgNPs, Maximum absorbance at 453.34nm wavelengths, the average size distribution of 27.12nm, the surface charge of -22.4mV, and spherical appearance were observed. LC-ESI-MS/MS analysis was used to assess the compound composition of D. kaki leaf extract. The chemical profiling of the crude extract of D. kaki leaves revealed the presence of a variety of phytochemicals, predominantly phenolics, resulting in the identification of five major high-feature compounds: two major phenolic acids (Chlorogenic acid and Cynarin), and tree flavonol glucosides (hyperoside, quercetin-3-glucoside, and quercetin-3- D-xyloside). The components with the highest concentrations were cynarin, chlorogenic acid, quercetin-3- D-xyloside, hyperoside, and quercetin-3-glucoside, respectively. Antimicrobial results were determined by a MIC assay. The biosynthesized AgNPs exhibited strong antibacterial activity against the human and food pathogen Gram (+ and -) bacteria and good antifungal activity against pathogenic yeast. It was determined that 0.03-0.050μg/mL concentrations ranges of DK-AgNPs were growth suppressive concentrations on all pathogen microorganisms. The MTT technique was used to study the cytotoxic effects of produced AgNPs on cancer cell lines (Glioblastoma (U118), Human Colorectal Adenocarcinoma (Caco-2), Human Ovarian Sarcoma (Skov-3) cancer cell lines, and Human Dermal Fibroblast (HDF) healthy cell line). It has been observed that they have a suppressive effect on the proliferation of cancerous cell lines. After 48h of treatment with Ag-NPs, the DK-AgNPs were found to be extremely cytotoxic to the CaCo-2 cell line, inhibiting cell viability by up to 59.49% at a concentration of 50gmL-1. It was found that the viability was inversely related to the DK-AgNP concentration. The biosynthesized AgNPs had dose-dependent anticancer efficacy. Because of the high concentration of bioactive chemicals in Diospyros kaki, it may be employed as a biological resource in medicinal applications. DK-AgNPs were shown to be an effective antibacterial agent as well as a prospective anticancer agent. The results provide a potential approach for the biogenic production of DK-AgNPs utilizing D. kaki aqueous leaf extract.

Water disinfection using durable ceramic filter coated with silver nanoparticles synthesized using actinomycetes

Contamination with pathogens degrades water quality and is a major cause of many waterborne diseases. The aim of this research is to reduce the global disease burden by presenting an efficient, durable, and low-cost ceramic filter impregnated with actinomycetes-mediated silver nanoparticles (AgNPs) for water disinfection in rural areas. This marks the first report on the simultaneous biosynthesis of AgNPs utilizing cell-free supernatants obtained from terrestrial actinomycetes. An easy and efficient method was used to impregnate AgNPs onto a ceramic filter using 3-aminopropyltriethoxysilane (APTES). The APTES linker is anchored to the ceramic surface through Si–O–Si bridges, while the terminal amino groups coordinate with AgNPs. Notably, the observed inhibition zone around the filter with AgNPs was ~ 18 mm, suggesting that the silver ions were responsible for the antibacterial activity. After 30 min of sonication, only insignificant traces of AgNPs were released from the filter, making it stable for long-term antibacterial activity when treating water. According to the laboratory simulation experiments, the untreated filter can reject about 99% of spiked bacteria, while the antibacterial efficiency of the filter coated with AgNPs was 100% due to the synergistic effect between filtration and disinfection with AgNPs. In addition, the average concentration of dissolved silver in the outlet water of the ultrafiltration system during three months was 33.7 μg/L, far below the permissible limit (100 μg/L) for drinking water. Overall, this work offers a suitable and affordable water treatment strategy for low-income, isolated, and rural societies in developing countries.