Synthesis Of AgNPs Research Articles

Green Synthesis of Poly (Vinyl Alcohol)‐Silver Nanoparticles Composite using Flaxseed (Linumusitatissimum L) Peel Extract: Its Cytotoxic and Antibacterial Activities

AbstractGreen synthesis of silver nanoparticles (AgNPs) by using diverse plant extracts has gained significance for applications in biomedical sciences and engineering. However, no studies have been done on the synthesis of AgNPs using the extract of Flaxseed peel (FsP) (Linumusitatissimum L), an eco‐friendly agricultural waste. The present study reports the green synthesis of poly (vinyl alcohol) (PVA) ‐ silver nanoparticles (PVA‐AgNPs) composite 1 using the aqueous extract of Flaxseed peel (FsP) (Linumusitatissimum L). GC‐MS, 1H NMR and FT‐IR spectral analyses were performed to understand the phytochemical basis of nanoparticle formation. The obtained AgNPs in the composite were characterized using a variety of techniques including FT‐IR, UV‐visible spectroscopy, HR‐TEM along with EDX spectroscopy, SEM, and DLS. UV‐vis analysis revealed a prominent surface plasmon resonance band at 422 nm, confirming the formation of AgNPs. TEM technique revealed the presence of nearly spherical AgNPs with an average size of 11.28 nm. PVA‐AgNPs composite 1 exhibited antibacterial activity against Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli. Furthermore, a dose‐time dependent cytotoxic effect against L929 fibroblast cells was demonstrated by the nanocomposite. Thus, present findings provided a basis of FsP‐extract mediated green synthesis of PVA‐AgNPs composite 1 suggesting functional nanomaterial of biomedical potentialities.

Synthesis of Silver Nanoparticles with <i>Syzygium aromaticum</i> Leaves Extract as Antioxidant and Antimicrobial Materials

Silver nanoparticles (AgNPs) have attracted attention due to their unique properties and potential application. This research aimed to do green synthesis of AgNPs with Syzygium aromaticum leaves extract (SALE) and evaluate their antibacterial and antioxidant activities. Syzygium aromaticum leaves were extracted using distilled water at 70 °C for 30 min and the results were characterized with FTIR. AgNPs were synthesized by mixing AgNO3 precursor with SALE. The effects of parameters such as volume ratio of AgNO3 precursor to SALE, AgNO3 concentrations, and synthesis times were investigated. The synthesized AgNPs were characterized using UV-Vis spectrophotometer, FTIR, and TEM. Antibacterial activity of SALE and AgNPs was investigated against Escherichia coli (E.coli) and Bacillus subtilis (B. subtilis) with disc diffusion method and antioxidant activity was tested with DPPH method. The FTIR characterization revealed that SALE and resulting AgNPs contain O-H, C-H, C=O, C=C, C-O, and C≡C functional groups. The UV-Vis characterization demonstrated that AgNPs exhibited an absorption peak at λ = 420 nm indicating surface plasmon resonance. The optimal volume ratio of AgNO3 to SALE, AgNO3 concentrations, and synthesis time for AgNPs synthesis was achieved at 10:3, 5 mM, and 60 min respectively. TEM characterization indicated that AgNPs have spherical form and sizes ranging from 14 to 32 nm. The antibacterial testing revealed that AgNPs have antibacterial activities against E. coli and B. subtilis with inhibition zone values are 8,38 ± 0,48 and 6,88 ± 1,47 respectively. Additionally, antioxidant testing presented that the IC50 values were 85.05 µg/mL for SALE and 34.71 µg/mL for AgNPs. The results indicate that green synthesis of AgNPs from AgNO3 precursor with SALE was done successfully and this nanoparticle has good antibacterial and antioxidant activities.

Study the Antifungal Effects of Green Synthesized Silver Nanoparticles on the Aspergillus niger, Microsporum canis, and Candida albicans

: The increasing prevalence of drug-resistant fungal pathogens and the limitations of current antifungal therapies underscore the need for novel alternative treatments. This study aimed to evaluate the antifungal effects of green-synthesized silver nanoparticles (Ag NPs) on three clinically significant fungi: Aspergillus niger, Microsporum canis, and Candida albicans. Silver nanoparticles were synthesized using plant-based extracts to ensure eco-friendly production methods. The synthesized Ag NPs were characterized using UV spectrophotometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential measurements, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Characterization assays revealed spherical particles with colloidal stability, an average size of approximately 80 nm, a Polydispersity Index of 0.4, and a surface charge of 62.3 mV. Minimum inhibitory concentration (MIC) values demonstrated effective suppression of fungal growth at low nanoparticle concentrations. In conclusion, our study highlights the potential of green-synthesized Ag NPs as a promising alternative to conventional antifungal agents, emphasizing their significant advantages in biocompatibility and eco-friendliness. These findings could pave the way for a new era in treating fungal infections, particularly those caused by drug-resistant strains.

Green Synthesis of Chrysanthemum morifolium Silver Nanoparticles and Evaluation of Its Antibacterial Activity

The increasing prevalence of microbial infections and antibiotic resistance has sparked interest in investigating the therapeutic potential of silver nanoparticles (AgNPs) as effective antimicrobial agents. The current study seeks to optimize the synthesis of AgNPs using Chrysanthemum morifolium (CM) extract and evaluate their antibacterial activity. Maximum synthesis of CM-AgNPs was achieved using 10 mM of AgNO3 and 20 mg/mL of CM extract at a 6:4 ratio and 3 hr of incubation period at pH 11 and 40°C. The Chrysanthemum morifolium-synthesized silver nanoparticles (CM-AgNPs) displayed a spherical shape, with sizes ranging from 12 to 34 nm. The minimum inhibitory concentration (MIC) against Pseudomonas mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae were 0.0117, 0.0117, 0.0031, and 0.100 mg/mL, respectively. CM-AgNPs demonstrated notable antibiofilm activity of 49.26%, 87.31%, and 66.23% against P. mirabilis, S. aureus, and K. pneumoniae, respectively. These results indicate that CM-AgNPs possess antibacterial properties and hold promise as antimicrobial agents.

Green-synthesis of silver nanoparticles AgNPs from Podocarpus macrophyllus for targeting GBM and LGG brain cancers via NOTCH2 gene interactions

Brain tumors, particularly Glioblastoma Multiforme (GBM) and Low-Grade Gliomas (LGG), present significant clinical challenges due to their aggressive nature and resistance to conventional treatments. Traditional therapies such as surgery, chemotherapy, and radiation are often limited in efficacy, necessitating novel therapeutic strategies. Nanotechnology, particularly the use of silver nanoparticles (Ag NPs), offers a targeted and potentially more effective approach. This study focuses on the green synthesis of Ag NPs using Podocarpus macrophyllus leaf extract as a reducing agent. The synthesized Ag NPs were characterized for their physicochemical properties, demonstrating a controlled particle size of 13 nm as determined by scanning electron microscopy (SEM). Fourier-transform infrared (FTIR) spectroscopy confirmed the presence of functional groups, and energy-dispersive X-ray (EDX) spectroscopy revealed that silver constituted approximately 90% of the nanoparticle composition. The Ag NPs exhibited promising biological activity, including 90% free radical scavenging (antioxidant) activity, 99.15% inhibition of protein denaturation (anti-inflammatory activity), and 90.56% inhibition of alpha-amylase (anti-diabetic activity). Additionally, the nanoparticles displayed significant anti-hemolytic (89.9% inhibition) and antimicrobial activities, with a 20 mm inhibition zone against Staphylococcus species. Computational analyses further indicated that the NOTCH2 gene, which is upregulated in LGG and GBM, may interact with Ag NPs, suggesting their potential in brain cancer therapy. The green synthesis approach offers a sustainable and bioactive method for producing Ag NPs, underscoring their therapeutic promise for treating GBM and LGG.

Exploring the green synthesis of silver nanoparticles using natural extracts and their potential for cancer treatment.

Silver nanoparticles (AgNPs) have attracted increasing attention in nanomedicine, with versatile applications in drug delivery, antimicrobial treatments, and cancer therapies. While chemical synthesis remains a common approach for AgNP production, ensuring environmental sustainability requires a shift toward eco-friendly, "green" synthesis techniques. This article underscores the promising role of plant extracts in the green synthesis of AgNPs, highlighting the importance of their natural sources and diverse bioactive compounds. Various characterization methods for these nanomaterials are also reviewed. Furthermore, the anticancer potential of green AgNPs (Gr-AgNPs) is examined, focusing on their mechanisms of action and the challenges to their clinical implementation. Finally, future directions in the field are discussed.

Utilizing Ziziphus spina-christi for eco-friendly synthesis of silver nanoparticles: Antimicrobial activity and promising application in wound healing

Abstract Wound healing is a critical process essential for the body’s recovery from injuries, often complicated by bacterial infections. Silver nanoparticles (AgNPs) have gained attention due to their antibacterial and tissue-regenerative properties. However, conventional chemical synthesis methods for AgNPs pose environmental risks. This study utilizes Ziziphus spina-christi (ZSC) extract for the eco-friendly synthesis of AgNPs, evaluating their antibacterial and wound-healing capabilities. The AgNPs-ZSC showed an absorption maximum at λ max of 460 nm, a particle size of 111.2 ± 1.09 nm, a polydispersity index of 0.38 ± 0.006, and a zeta potential of −27.0 ± 0.231 mV. The synthesized AgNPs-ZSC were spherical, non-aggregated, and exhibited potent antibacterial activity superior to chloramphenicol. Furthermore, the AgNPs-ZSC cream significantly promoted wound closure, epithelial tissue proliferation, and granulation tissue formation in rats, showing no signs of toxicity or adverse reactions. In conclusion, AgNPs-ZSC cream demonstrates excellent antibacterial and wound-healing properties, presenting a sustainable alternative to conventional chemical methods for AgNP synthesis.

A highly sensitive β-AKBA-Ag-based fluorescent “turn off” chemosensor for rapid detection of abamectin in tomatoes

Abstract This study presents the synthesis of a sensitive AKBA-Based fluorescent “Turn off” chemosensor for rapid detection of abamectin residues in tomatoes. Silver nanoparticles were synthesized by using 3-O-acetyl-11-keto-β-boswellic acid (β-AKBA) by chemical reduction method. The characterization of AKBA-AgNPs was performed by UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The average particle size of NPs was found to be 46.2 ± 2 nm with lumps of macro-sized particles. TEM data further revealed that nanoparticles were polydispersed and spherical in shape and also show good stability at high temperatures and pH. The biosensing properties of nanoparticles were studied for the detection of abamectin residues in tomato samples. Abamectin a natural product derived from the bacterium Streptomyces avermitilis is effective against a wide range of pests. In sensing protocol 67 organic tomato samples were segregated into 34 (safe group, without a spray of abamectin) and 33 samples (as an unsafe group, sprayed with abamectin insecticide solution). Emission spectra of these sample solutions were measured in the wavelength range of 450–530 nm, excitation wavelength was fixed at 488 nm. The effect of minor wavelength variation for the discrimination and classification of the two groups was investigated by applying two chemometric methods including partial least square discriminant analysis and principal component analysis with projection. The mechanism of its interaction between the AKBA-Ag NPs and abamectin residue was also established through UV/visible, FTIR, and TEM microscopy. This newly synthesized nanoparticle was found to have excellent stability at variables, i.e., temperature, storage period, salt concentration, and pH. Therefore, the synthesized Ag NPs are potential candidates for biosensing applications against abamectin.

Dual-Function Femtosecond Laser: β-TCP Structuring and AgNP Synthesis via Photoreduction with Azorean Green Tea for Enhanced Osteointegration and Antibacterial Properties.

β-Tricalcium phosphate (β-TCP) is a well-established biomaterial for bone regeneration, highly regarded for its biocompatibility and osteoconductivity. However, its clinical efficacy is often compromised by susceptibility to bacterial infections. In this study, we address this limitation by integrating femtosecond (fs)-laser processing with the concurrent synthesis of silver nanoparticles (AgNPs) mediated by Azorean green tea leaf extract (GTLE), which is known for its rich antioxidant and anti-inflammatory properties. The fs laser was employed to modify the surface of β-TCP scaffolds by varying scanning velocities, fluences, and patterns. The resulting patterns, formed at lower scanning velocities, display organized nanostructures, along with enhanced roughness and wettability, as characterized by Scanning Electron Microscopy (SEM), optical profilometry, and contact angle measurements. Concurrently, the femtosecond laser facilitated the photoreduction of silver ions in the presence of GTLE, enabling the efficient synthesis of small, spherical AgNPs, as confirmed by UV-vis spectroscopy, Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR). The resulting AgNP-embedded β-TCP scaffolds exhibited a significantly improved cell viability and elongation of human bone marrow mesenchymal stem cells (hBM-MSCs), alongside significant antibacterial activity against Staphylococcus aureus (S. aureus). This study underscores the transformative potential of combining femtosecond laser surface modification with GTLE-mediated AgNP synthesis, presenting a novel and effective strategy for enhancing the performance of β-TCP scaffolds in bone-tissue engineering.

Potential protective efficacy of biogenic silver nanoparticles synthesised from earthworm extract in a septic mice model

Sepsis is an inevitable stage of bacterial invasion characterized by an uncontrolled inflammatory response resulting in a syndrome of multiorgan dysfunction. Most conventional antibiotics used to treat sepsis are efficacious, but they have undesirable side effects. The green synthesised Ag NPs were synthesized by 5 g of the earthworm extract dissolved in a volume of 500mL of distilled water and then added to 2,500 mL aqueous solution of 1mM silver nitrate at 40 °C. After 4 h, the mixture was then allowed to dry overnight at 60 °C. Later, Ag NPs were washed and collected. They were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, and transmission electron microscopy. Sepsis model as induced by feces-intraperitoneal injection method. Eighteen male mice were assigned into three main groups: the control group, the sepsis-model group, and the Ag NPs-treated group. The control group received a single oral dose of distilled water and, after two days, intraperitoneally injected with 30% glycerol in phosphate buffer saline. The Sepsis-model group received a single oral dose of distilled water. Ag NPs - The treated group received a single oral dose of 5.5 mg/kg of Ag NPs. After two days, the sepsis-model group and Ag NPs-treated group were intraperitoneally injected with 200 µL of faecal slurry. Ag NPs treatment in septic mice significantly decreased liver enzyme activities, total protein, and serum albumin. Moreover, Ag NPs significantly enhanced kidney function, as indicated by a significant decrease in the levels of creatinine, urea, and uric acid. In addition, Ag NPs showed a powerful antioxidant effect via the considerable reduction of malondialdehyde and nitric oxide levels and the increase in antioxidant content. The histopathological investigation showed clear improvement in hepatic and kidney architecture. Our findings demonstrate the protective efficacy of biogenic Ag NPs against sepsis-induced liver and kidney damage.

Eco-Friendly Photocatalytic Treatment of Dyes with Ag Nanoparticles Obtained through Sustainable Process Involving Spirulina platensis

The development of efficient photocatalysts is crucial in addressing water pollution concerns, specifically in the removal of organic dyes from wastewater. In this context, the use of silver nanoparticles (Ag NPs) might represent a method to achieve high dye degradation efficiencies. On the other hand, the classical Ag NP production process involves several reactants and operating conditions, which make it poorly sustainable. In the present work, Ag NPs were synthesized according to a new sustainable process involving the use of natural extracts of Spirulina platensis and milder operating conditions. The material was also calcined to determine the influence of organic content on the properties of Ag NPs. The X-ray diffraction (XRD) analysis displayed the AgCl and Ag phases with a crystalline size of 11.79 nm before calcination. After calcination, only the Ag phase was present with an increased crystalline size of 24.60 nm. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the capping role of the metabolites from the extract. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) revealed the spherical or quasi-spherical morphologies with agglomeration due to the calcination. Energy-dispersive X-ray spectroscopy (EDX) and Thermogravimetric (TGA) analyses further confirmed the involvement of metabolites in the synthesis of Ag NPs. The optical changes in the products were observed in a UV-Vis analysis. The Ag NPs were tested for their photocatalytic activity against the laboratory dye brilliant blue r in visible light in various conditions. The highest degradation efficiency of 81.9%, with a kapp value of 0.00595 min−1, was observed in alkaline medium after 90 min of light irradiation.

Sonication-Assisted Electrochemical Synthesis of Silver Nanoparticles.

In this work, we propose a method for synthesizing silver nanoparticles (Ag NPs) utilizing a sonication-assisted electrochemical approach with a common ultrasonic cleaner. Silver nitrate is employed as the precursor and polyvinylpyrrolidone functions as the ligand. The incorporation of sonication is identified as crucial for achieving several benefits such as enhanced mass transfer, improved dispersion of reactants, and the prevention of electrode fouling. Optimized sonication and electrochemical conditions synergistically contribute to a higher yield of well-dispersed Ag NPs, which are characterized by an average size of 10 nm. Furthermore, the electrode's suitability for the continuous synthesis of Ag NPs over an extended period is highlighted owing to effective electrode surface cleaning facilitated by sonication. This cleaning process proves to be essential in maintaining the electrochemical activity of the electrode, ensuring consistency in the synthesis process. The proposed sonication-assisted electrochemical synthesis method not only addresses challenges associated with electrode fouling but also significantly enhances the dispersity and yield of the resulting particles, making it valuable for scalability and practical applications in various fields, including sensors, catalysis, and nanotechnology.

Green Synthesis of Silver Nanoparticles from Abelmoschus esculentus (Okra) Calyx Wastes as a Promising Anthelmintic Agent Against Poultry Pathogen Raillietina spp.

AbstractIn this study, we explore the synthesis of silver nanoparticles (AgNPs) using calyx wastes from Abelmoschus esculentus (okra) and evaluate their anthelmintic potential against poultry pathogen Raillietina spp. The ultraviolet‐visible (UV‐vis) spectrum of nanoparticles showed an absorbance peak at 425 nm, confirming AgNP formation. Fourier transform infrared spectrophotometry (FTIR) analysis indicated the presence of functional groups responsible for reducing silver ions, and X‐ray diffraction (XRD) patterns confirmed the crystallinity of the nanoparticles. Dynamic light scattering (DLS), scanning and transmission electron microscopy (SEM and TEM) analyses were used to measure the size (20–50 nm) and morphology (spherical) of the synthesized AgNPs. The dose‐dependent in vitro anthelmintic efficacy was highest at 125 μg/ml of AgNPs, resulting in paralysis and death within 0.54 and 1.29 hours, respectively, while untreated control parasites survived for ~72 hours. The SEM micrographs of the treated parasites showed swelling and blebbing of the tegument. Histochemical localization studies showed a remarkable decline of tegumental and neurotransmitter enzymes involved with the parasite's metabolism and regulation of the endogenous physiological processes. This study underscores the potential of okra calyces in the green synthesis of AgNPs and provides a novel approach to developing alternative anthelmintics that interfere with the host‐parasite interface.

Biogenic Synthesis of Ag NPs Adorned Gellan Gum Modified Fe3O4 NPs Towards the Catalytic Reduction of Nitroarenes and the Investigation of Anti-breast Cancer Potential

Biogenic Synthesis of Ag NPs Adorned Gellan Gum Modified Fe3O4 NPs Towards the Catalytic Reduction of Nitroarenes and the Investigation of Anti-breast Cancer Potential

Phyto-mediated biosynthesis of silver nanoparticles using Aloe barbadensis Miller leaves gel with improved antibacterial, anti-fungal, antioxidant, anti-inflammatory, anti-diabetic, and anti-cancer activities

An effective topical therapeutic agent requires a multifunctional attribute such as antibacterial, antioxidant, and anti-inflammatory efficacy. The green-synthesized metallic and metallic oxide nanoparticles have shown significant applicability in this regard. Hence a biosynthesis of silver nanoparticles (AgNPs) using Aloe barbadensis miller leaf gel was fabricated and evaluated for effect of imperative influences such as temperature, time, and concentration of reactant on AgNPs synthesis. Furthermore, the biomimetic qualities were assessed to ensure the safety and efficacy. The synthesis of stabilized and capped AgNPs presented a UV–vis–based plasmonic resonance at ∼ 400 nm. The reduction of silver nitrate was further confirmed by the shift in FTIR spectra for -OH around 2870 cm−1. SEM and TEM images revealed cubic shape of the AgNPs. Whereas X-ray diffraction pattern indicated crystalline structure (crystallite size of ∼ 31.14 nm) with an inter-planar spacing value of 2.77, 1.96, and 1.67 Å for (200), (220), and (311) planes, respectively. In addition, AgNPs indicated a steady dispersion, homogeneity, and strong anionic zeta potential (∼ 35.4 mV). The results of antibacterial and antifungal activity demonstrated the potential of phyto-synthesized AgNPs in mitigation of infection associated with tested bacterial strain Bacillus subtilis, Bacillus megaterium, Shigella flexneri, Trichoderma viride, Aspergillus niger, and Penicillium crysogenum. Moreover, the results of hydrogen peroxide-based scavenging, anti-inflammatory, and anti-diabetic study revealed that the biosynthesized AgNPs exhibit an improved biomimetic attribute. Additionally, the biocompatibility assay demonstrated > 80 % of CaCO-2 and L-929 cells viability at 1.67 μg/mL and 3.35 μg/mL, respectively. The anticancer activity of synthesized AgNPs against epithelium-like phenotype oral squamous carcinoma cells (CLS-354/WT) displayed IC50 of 11.58 μg/mL. The results indicate that biogenic produced AgNPs may find suitable use as a potential therapeutic agent due to multifunctional attribute.

Green Synthesis of Dracocephalum kotschyi-Coated Silver Nanoparticles: Antimicrobial, Antioxidant, and Anticancer Potentials.

BACKGROUND The environmentally friendly production of silver nanoparticles (AgNPs) has gained significant attention as a sustainable alternative to traditional chemical methods. This study focused on synthesizing AgNPs using extract of Dracocephalum kotschyi (D. kotschyi), a medicinal plant. MATERIAL AND METHODS The biosynthesis of AgNPs was monitored using UV-visible spectrophotometry. The role of phytoconstituents from D. kotschyi in stabilizing AgNPs was analyzed using Fourier-transform infrared (FTIR) spectroscopy. Dynamic light scattering (DLS) spectroscopy was used to determine the size, charge, and polydispersity of the nanoparticles, while scanning electron microscopy (SEM) was employed to assess their morphology. We evaluated the antimicrobial efficacy of the synthesized AgNPs against various bacteria, their antioxidant properties via a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, and their cytotoxic activity against the HeLa cervical cancer cell line. RESULTS The formation of AgNPs was indicated by a color change and the emergence of a surface plasmon resonance peak at 418 nm. The nanoparticles demonstrated significant antimicrobial, antioxidant, cytotoxic, and anticancer activities. Morphology, size, and shape analysis revealed nearly spherical particles with an average size of 43 nm. FTIR confirmed the presence of phenolic compounds in the extract, serving as reducing and capping agents. X-ray diffraction (XRD) analysis confirmed the crystalline structure of the nanoparticles. Antimicrobial assessments showed effectiveness against Escherichia coli and Staphylococcus aureus. The DPPH scavenging assay demonstrated efficient antioxidant activity, and potent apoptotic anticancer effects were observed on cervical cancer cells. CONCLUSIONS The extract of D. kotschyi was effective as a reducing agent in the environmentally friendly synthesis of AgNPs, which exhibited noteworthy antimicrobial, antioxidant, and anticancer properties. These findings suggest potential biomedical applications for the synthesized AgNPs.

Cyanobacterial Silver Nanoparticles and Their Potential Utility-Recent Progress and Prospects: A Review.

The current situation involves an increase in interest in nanotechnology, in particular the ways in which it can be applied in the commercial and medical fields. However, traditional methods of synthesizing nanoparticles have some drawbacks, including the generation of harmful byproducts, high energy consumption, and cost. As a result, researchers have shifted their focus to "green" nanoparticle synthesis to circumvent these drawbacks. Because of their exceptional physiochemical properties, silver nanoparticles (Ag Nps) are the noble metal nanoparticles that are used most frequently. The green approach to Ag NP synthesis is environmentally friendly, non-toxic, and cost-effective, and it makes use of a variety of biological entities. Cyanobacteria, in particular, have garnered the most attention because of the abundance of bioactive substances that they contain, which serve both as reducing agents and as stabilizing agents during the process of biosynthesis. This review article discusses the current state of cyanobacteria-mediated Ag NP synthesis, the potential mechanisms that are involved, nanoparticle characterization, the various applications of Ag NP in different fields, and their prospects.

Effect of surface charge on laser-produced silver nanoparticles for dye reduction and surface-enhanced Raman spectroscopy

Silver nanoparticles (Ag NPs) are widely used in biological, chemical, and physical fields due to their distinct properties. However, the effect of surfactants with different polarities on the catalytic and surface-enhanced Raman spectroscopy (SERS) performance of Ag NPs has not been thoroughly studied. Here, we tailor the surface charge of laser-synthesized Ag NP without changing their morphology and investigate their catalytic and SERS capabilities. The surfactant-free silver nanoparticles (NPBare), synthesized via pulsed laser ablation in liquid (PLAL), are subsequently coated with ionic surfactants sodium dodecyl sulfate (NPSDS) and cetyltrimethylammonium bromide (NPCTAB). The synthesis and morphology of Ag NPs are confirmed using UV-Vis absorption spectroscopy and scanning electron microscopy. The surface charge of fabricated NPs is determined using zeta potential (ZP) measurements. The ZP values of NPBare, NPSDS, and NPCTAB are determined to be -17 mV, 28.7 mV, and 5.58 mV, respectively. The catalytic activity of bare and coated Ag NPs was tested against the cationic and anionic dyes, Methylene blue (MB) and Methyl orange (MO) respectively. The reduction rate of both dyes was highest when using NPBare. However, in the case of coated nanoparticles, the rate of MB and MO reduction depends on the difference between the ZP of the dye and nanoparticles: the rate of reduction increases with the difference between the zeta potentials of the dye and coated nanoparticles increases. The SERS capability of bare and coated NPs was evaluated for anionic (MO) and cationic (MB, Rhodamine B, and Crystal Violet) dyes. The SERS intensity of dyes strongly enhanced with the increase in ZP difference between the dye molecules and NPs. Surface charge modified NPs shown excellent SERS sensitivity with detection limit up to nanomolar for dye molecules as well as the homogeneity of NPs demonstrated in Raman mapping results with relative standard deviation of 17%. The results suggest that the electrostatic interaction between the nanoparticles and dye molecules plays a dominant role in SERS enhancement. These findings highlight the significance of surface charge in improving the catalytic and sensing properties of noble metal nanoparticles.

Holistic exploration of silver nanoparticles synthesized from Carthamus oxycantha leaf extracts: Characterization and assessment of antioxidant, anti-α-amylase, and anti-cholinesterase activities using comprehensive statistical methods

In the burgeoning field of nanotechnology, plant-mediated nanoparticles (NPs) have attracted significant attention due to their small size, favorable chemical properties, and eco-friendly nature. We utilized Carthamus oxycantha leaf extract to synthesize silver nanoparticles (AgNPs) and evaluate their potential as antioxidants and inhibitors of acetylcholinesterase (AChE) and alpha-amylase (α-amylase). The AgNPs were characterized using advanced techniques. The UV–Vis spectrum recorded at 410 nm, with an absorbance of 2.3 a.u., confirmed the presence of AgNPs. Fourier transform infrared spectroscopy (FT-IR) indicated that functional groups from the extract were attached to the AgNP surface, aiding in their formation and stabilization. X-ray diffraction analysis (XRD) revealed four major peaks at 37, 43, 64, and 77, confirming AgNP synthesis. Scanning electron microscopy (SEM) showed that 80 % of the AgNPs were spherical, measuring 25–50 nm, while energy dispersive X-ray (EDX) analysis indicated that silver constituted 83 % of the material. The AgNPs demonstrated significant scavenging activity: 59.3 % with ABTS, 67.2 % with ammonium molybdate, 60.35 % with DPPH, 65.2 % with ferric chloride, and 55.2 % with H2O2. Both α-amylase and AChE were inhibited by AgNPs, exhibiting uncompetitive inhibition characteristics. For glucophage, Km decreased from 143 to 75 µg, and Vmax decreased from 45 % to 72 % as concentrations increased from 50 to 150 µg. The Km of AgNPs decreased from 25 to 17 µg, and Vmax decreased from 16 % to 37 %. The extract showed noncompetitive inhibition against α-amylase, while AgNPs caused noncompetitive inhibition in AChE. These findings highlight the potential of AgNPs as therapeutic agents for managing oxidative stress and enzyme-related disorders, paving the way for future research and applications in medicinal chemistry.

Synthesis of Silver Nanoparticles Using Plant Extracts from Legeneraria Siceraria Fruits and Assessment of their Anti-Bacterial and Anti-Oxidant Activities

Nanotechnology is a key subject of science, engineering, and technology that is experiencing enormous growth in the current century. In this study, fruits of the legeneraria siceraria plant, this is widely used in traditional medicines in Ethiopian rural areas, used as reducing and capping agent for AgNPs synthesis. The legeneraria siceraria fruits -mediated synthesized AgNPs characterized by ultravioletvisible (UV-VIS.) spectrophotometry, Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffractometer (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS). The optimal synthesization parameters for AgNPs in this study were temperature 60 °C, stirring time 60 minutes, pH 11, and 2 mM silver nitrate concentration. Characteristic and well-defined SPR bands for AgNPs were confirmed at around λmax = 426 nm. Synthesized AgNPs of calculated mean crystallite size were 10.21 nm. Scanning electron microscopy (SEM) revealed the synthesized AgNPs have a spherical structure. The antibacterial activity of AgNPs synthesized using legeneraria siceraria fruits medicinal plants demonstrated that Gram-positive and Gram-negative bacteria inhibited. Additionally, the AgNPs showed minimal toxicity to human cells. AgNPs were useful antioxidants for health preservation against different oxidative stress associated with degenerative diseases. In this work, it acts at scavenging against DPPH.