Nm For AgNPs Research Articles

A time and temperature dependent biosynthesis of silver nanoparticles using the extract of Platycladus orientalis’ fruit

Silver nanoparticles (AgNPs) have gained notable/ huge attention, particularly in the biomedical and antibacterial fields, owing to their distinctive characteristics. Biological synthesis of AgNPs is a prominent method due to its ease of preparation, eco-friendliness, non-toxicity and time efficiency. Herein, AgNPs were synthesized using an extract from "Platycladus orientalis" and their antimicrobial and biological properties were thoroughly investigated. The scaling down of Ag⁺ to Ag⁰ was evident through the appearance of a yellow brownish colour. AgNPs were characterized by UV–Visible spectrum, X-ray diffraction (XRD), and scanning electron microscopy (SEM). UV–Visible spectroscopy revealed absorption peaks at around 440 nm for AgNPs synthesized from fruits’ seat coat of Platycladus orientalis. TEM analysis indicates the average size of AgNPs is approximately 50 nm. Powder XRD confirmed the crystalline nature of the AgNPs, with prominent peaks corresponding to face-centred cubic structures. FTIR analysis identified key functional groups involved in the synthesis process. SEM images displayed agglomerated AgNPs with varying diameters and particle dispersion. Molecular docking results showed favourable binding interactions of AgNPs with the protein 2BTD, with a docking score of -3342 kcal/mol, indicating potential biological activity. These findings highlight the effective synthesis of AgNPs using Platycladus orientalis and their significant potential for biomedical applications.

REMOVAL OF LEAD IONS BY GREEN SYNTHESIZED SILVER NANOPARTICLES USING AQUEOUS EXTRACTS OF PROSOPIS JULIFLORA AND MENTHA PIPERITA L. LEAVES

Heavy metal compounds are commonly used as required industrial materials. Heavy metal ions are known to possess poisonous properties. Lead (II) ion is one of them; it is more toxic and carcinogenic. The contamination of water with Pb (II) may lead to kill people who drink it, in addition to harmful effects on plants and animals. Therefore, Pb (II) ions must be removed from the polluted water. In this work, an eco-friendly method was employed to synthesize silver nanoparticles (AgNPs) from silver nitrate and two separate plant extracts; leaves of Prosopis Juliflora and Mentha Piperita L. AgNPs were used to remove Pb (II) ions from aqueous solutions through the adsorption process. The synthesized AgNPs were identified by ultraviolet- visible (UV-Vis), Fourier-transform infrared (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis. The diameters of formation nanoparticles were within the range of 8.06–11.5 and 8.02- 11.5 nm of AgNPs from Prosopis Juliflora, and AgNPs from Mentha Piperita L. extracts, respectively. During the adsorption process, the influence of adsorbent dose, Pb (II) ion concentration, and contact time in removing were studied at constant temperature and constant pH.

Assessment of the Effect of Surface Modification of Metal Oxides on Silver Nanoparticles: Optical Properties and Potential Toxicity.

Silver nanoparticles (AgNPs) have garnered significant interest due to their distinctive properties and potential applications. Traditional fabrication methods for nanoparticles often involve high-energy physical conditions and the use of toxic solvents. Various green synthesis approaches have been developed to circumvent these issues and produce environmentally benign nanoparticles. Our study focuses on the green synthesis of AgNPs using L-ascorbic acid and explores the modification of their properties to enhance antibacterial and anticancer effects. This is achieved by coating the nanoparticles with Zinc oxide (ZnO) and Silica oxide (SiO2), which alters their optical properties in the visible spectrum. The synthesized formulations-AgNPs, zinc oxide-silver nanoparticles (Ag@ZnO), and silica oxide-silver nanoparticles (Ag@SiO2) core/shell nanoparticles-were characterized using a suite of physicochemical techniques, including Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta potential measurement, UV-Vis spectroscopy, Refractive Index Measurements, and Optical Anisotropy Assessment. TEM imaging revealed particle sizes of 11 nm for AgNPs, 8 nm for Ag@ZnO, and 400 nm for Ag@SiO2. The Zeta potential values for Ag@ZnO and Ag@SiO2 were measured at -17.0 ± 5 mV and -65.0 ± 8 mV, respectively. UV-Vis absorption spectra were recorded for all formulations in the 320 nm to 600 nm wavelength range. The refractive index of AgNPs at 404.7 nm was 1.34572, with slight shifts observed for Ag@ZnO and Ag@SiO2 to 1.34326 and 1.37378, respectively. The cytotoxicity of the nanocomposites against breast cancer cell lines (MCF-7) was assessed using the MTT assay. The results indicated that AgNPs and Ag@ZnO exhibited potent therapeutic effects, with IC50 values of 494.00 µg/mL and 430.00 µg/mL, respectively, compared to 4247.20 µg/mL for Ag@SiO2. Additionally, the antibacterial efficacy of AgNPs was significantly enhanced under visible light irradiation. Ag@ZnO demonstrated substantial antibacterial activity both with and without light exposure, while the Ag@SiO2 nanocomposites significantly reduced the inherent antibacterial activity of silver. Conversely, the Ag@ZnO nanocomposites displayed pronounced antibacterial and anticancer activities. The findings suggest that silver-based nanocomposites, particularly Ag@ZnO, could be practical tools in water treatment and the pharmaceutical industry due to their enhanced therapeutic properties.

Correlation between electrical conductivity and antibacterial activity of chitosan-stabilized copper and silver nanoparticles

In this study chemical reduction method is used to synthesize the copper and silver nanoparticles. Chitosan was utilized as a stabilizing agent, a suitable medium for nanoparticle growth, and to stop the oxidation and aggregation of the particles. Various characterization such as FTIR Spectra, UV spectra, PL spectra, XRD, EDAX, TEM and Zeta potential approaches were used to examine the copper and silver nanoparticles. The antibacterial activity was assessed through the disc diffusion method. The antibacterial activity to the selected human pathogens, which included two bacterial pathogens such as S. pyogenes and K. pneumoniae as well as one fungal pathogen, Candida albicans . The size and shape of the synthesized CuNPs and AgNPs were evaluated using TEM. The average size distribution is 23.65 nm for CuNPs and 21.76 nm for AgNPs. Copper and AgNPs show antibacterial efficacy against two bacterial strains and a fungi strain. The AgNPs show significant antibacterial activity in comparison with the Chitosan and CuNPs.

Green synthesis of Superparamagnetic Iron Oxide and Silver Nanoparticles in Satureja hortensis Leave Extract: Evaluation of Antifungal Effects on Botryosphaeriaceae Species.

In recent years, green synthesis methods of metallic nanoparticles (MNPs) have been attractive because of the more facile, cheaper, and appropriate features associated with biomolecules in MNPs biosynthesis. This research represented an easy, fast, and environmentally friendly method to biosynthesis of superparamagnetic iron oxide nanoparticles (SPIONPs) and silver nanoparticles (AgNPs) by the Satureja hortensis leaf extract as stabilizer and reducer. The SPIONPs synthesized in co-precipitation method. The biosynthesized SPIONPs and AgNPs were studied their antifungal effects against three Botryosphaeriaceae plant pathogens, Botryosphaeria dothidea, Diplodia seriata, and Neofusicoccum parvum. UV-visible spectra (UV-Vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (Fe-SEM), energy-dispersive X-ray spectroscopy (EDX), and vibrating-sample magnetometer (VSM) analyses were used to evaluate the physicochemical properties and verify the formation of green synthesized SPIONPs and AgNPs. UV-Vis spectra revealed absorption peaks at 243 and 448 nm for SPIONs and 436 nm for AgNPs, respectively. Microscopic and XRD analysis showed that SPIONPs and AgNPs was found spherical in shape with an average particle size of SPIONPs and AgNPs 10 and 12 nm, respectively. The antifungal test against Botryosphaeriaceae species showed that SPIONPs and AgNPs possessantifungal properties against B. dothidea, D. seriata, and N. parvum. However, AgNPs exhibits greaterantifungal activity than SPIONPs. Theresultsof thecytotoxicitytests of SPIONs and AgNPs on the MCF-7 cell line showed that AgNPs was significantly more cytotoxictowardsthe MCF-7 cell line, whereas nosignificant cytotoxiceffect was recorded by SPIONs. Therefore, these biosynthesized MNPs could be substituted for toxic fungicides that are extensively applied in agriculture and contribute to environmental health and food safety.

Formulation and evaluation of azithromycin-loaded silver nanoparticles for the treatment of infected wounds

Infected wounds pose a significant challenge in healthcare, requiring innovative therapeutic strategies. Therefore, there is a critical need for innovative pharmaceutical materials to improve wound healing and combat bacterial growth. This study examined the efficacy of azithromycin-loaded silver nanoparticles (AZM-AgNPs) in treating infected wounds. AgNPs synthesized using a green method with Quinoa seed extract were loaded with AZM. Characterization techniques, including X-ray Powder Diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Uv-Vis analysis were utilized. The agar diffusion assay and determination of the MIC were used to assess the initial antibacterial impact of the formulations on both MRSA and E. coli. In addition, the antimicrobial, wound-healing effects and histological changes following treatment with the AZM-AgNPs were assessed using an infected rat model. The nanoparticles had size of 24.9 ± 15.2 nm for AgNPs and 34.7 ± 9.7 nm for AZM-AgNPs. The Langmuir model accurately characterized the adsorption of AZM onto the AgNP surface, indicating a maximum loading capacity of 162.73 mg/g. AZM-AgNPs exhibited superior antibacterial properties in vivo and in vitro compared to controls. Using the agar diffusion technique, AZM-AgNPs showed enhanced zones of inhibition against E. coli and MRSA, which was coupled with decreased MIC levels. In addition, in vivo studies showed that AZM-AgNP treated rats had the best outcome characterized by improved healing process, lower bacterial counts and superior epithelialization, compared to the control group. In conclusion, AZM-AgNPs can be synthesized using a green method with Quinoa seed with successful loading of azithromycin onto silver nanoparticles. In vitro and in vivo studies suggest the promising use of AZM-AgNPs as an effective therapeutic agent for infected wounds.

Green synthesis of silver and gold nanoparticles in Callistemon viminalis extracts and their antimicrobial activities.

In the current study, the bottlebrush [Callistemon viminalis (Sol. ex Gaertn.) G. Don] plant was selected for the green synthesis of silver (Ag) and gold (Au) nanoparticles and to evaluate its antibacterial and antifungal activities. Phytochemical screening of C. viminalis confirmed the presence of alkaloids, anthraquinones, saponins, tannins, betacyanins, phlobatanins, coumarins, terpenoids, steroids, glycosides, and proteins. To characterize the synthesized Ag and Au NPs, UV-Visible spectroscopy, FTIR spectroscopy for functional group identification, field emission scanning electron microscopy (FE-SEM) for particle size, and elemental analysis were performed using EDX. The UV-Visible absorption spectra of the green-synthesized Ag and Au nanoparticles were found to have a maximum absorption band at 420 nm for Ag NPs and 525 nm for Au NPs. FE-SEM analysis of the synthesized NPs revealed a circular shape with a size of 100 nm. Elemental analysis was performed for the synthesis of Ag and Au NPs, which confirmed the purity of the nanoparticles. The greenly synthesized Ag and Au NPs were also evaluated for their anti-bacterial and anti-fungal activities, which exhibited prominent inhibition activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, C. krusei, Aspergillus sp., and Trichoderma species. The highest zone of inhibition 15.5±0.75 and 15±0.85mm was observed for Ag NPs against E. coli and P. aeruginosa. Similarly, Trichoderma sp. and Aspergillus sp. were inhibited by Ag NPs up to 13.5±0.95 and 13±0.70mm. This work will open doors for the development of new antimicrobial agents using green chemistry.

Characterization and Eco-Friendly Synthesis of Silver and Iron Nanoparticles Using Microalgae Extracts: Implications for Nanobiotechnology.

<b>Background and Objective:</b> The remarkable surface-to-volume ratio and efficient particle interaction capabilities of nanoparticles have garnered significant attention among researchers. Microalgal synthesis presents a sustainable and cost-effective approach to nanoparticle production, particularly noteworthy for its high metal uptake and ion reduction capabilities. This study focuses on the eco-friendly and straightforward synthesis of Silver (AgNPs) and Iron (FeNPs) nanoparticles by utilizing Spirulina (<i>Arthrospira platensis</i>) and <i>Chlorella pyrenoidosa</i> extract, devoid of any chemical reducing or capping agents. <b>Materials and Methods:</b> Following the mixing of 1 mM AgNO<sub>3</sub> and 1 mM iron oxide solution with the algal extract, the resulting filtrated solution underwent comprehensive characterization, including UV-visible absorption spectra analysis, observation of particle morphology, Zetasizer measurements and Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) analysis. <b>Results:</b> The UV-visible spectroscopy revealed a maximum absorbance peak at 430-440 nm, confirming the successful green synthesis of AgNPs and FeNPs, as indicated by the distinct color change from transparent to dark reddish-yellow and brown to reddish-brown, respectively. The SEM-EDX analysis further elucidated the spherical morphology of the nanoparticles, with an average diameter of 93.71 nm for AgNPs and 6198 nm for FeNPs. The Zeta potential measurements indicated average values of -56.68 mV for AgNPs and 29.73 mV for FeNPs, with conductivities of 0.1764 and 0.6786 mS/cm, respectively. <b>Conclusion:</b> The observed bioaccumulation of silver and iron nanoparticles within the algal extract underscores its potential as an environmentally friendly and cost-effective method for nanoparticle synthesis. These findings suggested a promising avenues for the application of silver and iron nanoparticles in the field of nanobiotechnology. Future research endeavors could focus on optimizing preparation conditions and controlling nanoparticle size to further enhance their utility and effectiveness.

Biosynthesis of Silver, Copper, and Their Bi-metallic Combination of Nanocomposites by Staphylococcus aureus: Their Antimicrobial, Anticancer Activity, and Cytotoxicity Effect

AbstractThe present study outlines an easy, cheap, and environmentally friendly way to make Staphylococcus aureus-mediated bimetallic silver-copper nanocomposites (Ag/Cu) that can fight cancer and germs. The gram-positive S. aureus synthesized Ag, Cu, and their bi-metallic nanocomposites extracellularly. We aimed to prepare the bimetallic nanocomposite in two different ways, and we compared them in terms of characterization and biological applications. The first one is a bimetallic nanocomposite (Ag/Cub) that was made by mixing Ag and Cu metal ions in equal amounts (50:50). Then, the whole mixture was reduced. The second is the after-reduction bimetallic nanocomposite (Ag/Cua), in which each metal ion was reduced separately, and then the nanocomposites were mixed (50:50%) during biological applications. Nanocomposites were characterized using UV–visible spectrophotometry, Fourier-transform infrared spectroscopy, dynamic light scattering, and transmission electron microscopy. The results demonstrated that surface plasmon bands were at 320 nm for Ag NPs and 525 nm for Cu NPs, and a shift from these peaks was observed at 290 nm in the Ag/Cub bimetallic nanocomposite. The synthesized nanocomposites were confirmed to be in the nanoscale with 20, 40, and 80 nm spherical crystals, respectively. Nanocomposites were assayed for their antimicrobial activity against the gram-negative Pseudomonas aeruginosa, the acid-fast Mycobacterium smegmatis, the gram-positive Bacillus cereus, and S. aureus, in addition to three fungal species, which were Aspergillus flavus, A. fumigatus, and Candida albicans. The minimum inhibitory concentration and minimum bactericidal concentration were determined. The Ag/Cua/Cuaetallic nanocomposite was the most potent antimicrobial compound. The anticancer activity of the tested compounds was assayed against the hepatocellular carcinoma cell line (HepG-2). Low cytotoxic activity was recorded in most assayed nanocomposites against the baby hamster kidney cell line (BHK).

Biogenic synthesis of silver, gold, and palladium nanoparticles using moringa oleifera seeds: exploring photocatalytic, catalytic, and antimicrobial activities

In this study, we explored the green synthesis of metal nanoparticles (Ag-NPs, Au-NPs, and Pd-NPs) using Moringa oleifera seed (MOS) extract, which is known for its nutrient density, antioxidant properties, anti-inflammatory effects, and potential benefits in managing cholesterol, blood sugar levels, as well as promoting digestion, skin, and hair health. The nanoparticles’ size was controlled by varying the concentration of MOS extract. The successful formation of Au-NPs and Ag-NPs was confirmed through surface plasmon resonance (SPR), while the absence of absorption at 420 nm indicated the reduction of Pd2+ ions to Pd0, affirming the synthesis of Pd-NPs. The nanoparticles exhibited mono-dispersed, spherical shapes with confirmed crystallinity. Sizes were determined as 28 nm for Pd-NPs, 5 nm for Au-NPs, and 19 nm for Ag-NPs. The MOS extract’s phenols and proteins played a crucial role in reducing and stabilising Ag-NPs, Au-NPs, and Pd-NPs. Notably, the synthesised nanoparticles demonstrated strong antimicrobial activity, particularly against Salmonella typhi, making them potential antibacterial agents. The catalytic efficiency of Au-NPs, Ag-NPs and Pd-NPs was studied using the reduction of 4-Nitrophenol (4-NP) by NaBH4 to 4-Aminophenol. Additionally, Au-NPs showed enhanced photocatalytic degradation rate constant and catalytic reaction rate constant of 0.0038/min and 0.261/min respectively, due to their small size and increased surface area. By combining a green synthesis approach with an in-depth analysis of properties and diverse applications, this study provides valuable insights into the immense potential of MOS-assisted metal nanoparticles for various technological and environmental advancements.

Sustainable solutions for clean water: Green synthesized Cu-Ag-Bimetallic nanoparticles based nano catalyst

The green synthesis of copper (Cu)-silver (Ag) bimetallic nanoparticles (Cu-Ag BMNPs) using Argyreia nervosa (AN) plant leaf extract as a dual reducing and stabilizing agent is an eco-friendly and sustainable method with significant potential for diverse photo-catalytic applications. This study explores the photo-catalytic activity of biosynthesized Cu-Ag-BMNPs employing methylene blue (MB) dye under visible light. FTIR analysis reveals bio-functional groups and chemical bands, while SEM and XRD analyses provide morphological and structural details. UV–Vis spectroscopy indicates absorption peaks at 300–350 nm for CuNPs, 350–550 nm for AgNPs, and 400–550 nm for Cu-Ag-BMNPs, with an optical band gap of 3.6 eV. The results demonstrate an 85% dye degradation rate, underscoring the efficiency of Cu-Ag-BMNPs as photo-catalysts for environmentally friendly remediation. We assessed the rate constant governing the degradation of MB dye by Cu-Ag-BMNPs, employing the pseudo-first-order kinetics model. This green synthesis approach not only minimizes hazardous chemical use but also leverages the inherent bioactive properties of the plant extract, showcasing promise in addressing water pollution through organic contaminant removal.

SILVER NANOPARTICLES INHIBIT INFECTIOUS BRONCHITIS VIRUS REPLICATION

Objective: Avian infectious bronchitis virus (IBV) threatens the poultry industry and causes global economic losses. The IBV is highly variable. Thus, no effective drugs are available. Objective of the present study was to evaluate silver nanoparticles against it as an antiviral agent. Methods: Silver nanoparticles (AgNPs) have been evaluated as antivirals against IBV. P. betle leaf extract biosynthesizes AgNPs from silver nitrate. UV/vis absorption, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) have been used to characterize AgNPs. TEM indicated particle sizes of 5–30 nm, and XRD demonstrated their characteristic AgNPs structure. The antiviral activity of AgNPs was measured by the log embryo infective dose 50 (logEID50)/ml and the number of IBV genome copies. Results: XRD analysis showed a structure for AgNPs, and transmission electron microscopy showed a size of 5–30 nm for AgNPs. AgNPs at a noncytotoxic concentration inhibit the interaction between the virus and the cell, preventing the virus from entering the cell and reducing the number of IBV genome copies (per µl) in ovo by preventing the formation of the IBV RNA genome, resulting in a significant reduction in the IBV titer. Conclusion: AgNPs possess antiviral properties that inhibit IBV replication in ovo. The findings indicate that AgNPs are a promising drug candidate for treating or preventing IBV infection.

Green synthesis of Ag and Au NPs decorated rGO nanocomposite for high impedimetric electrochemical sensor as well as enhanced antimicrobial performance against foodborne pathogens

In the present study, Allium cepa L. leaves extract mediated silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) decorated reduced graphene oxide (Ag/Au/rGO NC’s) were synthesized and demonstrated their biological and electrochemical sensing applications. Interestingly, the synthesis of AgNPs and AuNPs was achieved rapidly within 1 h and 4 h, respectively. Whereas the production of both reduced graphene oxide (rGO) and Ag/Au/rGO NC’s was achieved at 96 h. The achieved results from the UV–Vis spectrum of 432 nm for AgNPs and 550 nm of AuNPs and the shifting of the characteristic GO absorption band of 230 nm into 270 nm as well as an absence of 305 nm confirmed the rGO synthesis. In addition, HR-XRD analyses confirmed the JCPDS file No. 04–0783 and 01–1174 pertaining to Ag and Au NPs. Further, the Raman spectroscopy, FT-IR and EDS analyses confirmed the evidence of nanomaterials biosynthesis. A polydisperse, spherical shaped average size AgNPs of 1 to 30 nm, spherical and triangular shaped AuNPs with an average size of 1 to 120 nm, and silk like appearance of a thin layered graphene sheet in rGO were observed through TEM. Also, the recorded results evident the uniform decoration of Ag and Au NPs into the rGO sheet. The electrochemical properties of as-synthesized materials were studied by electrochemical impedance spectroscopic (EIS) and cyclic voltammetry (CV) techniques. Interestingly, the Ag/Au/rGO NC’s modified electrode exhibited higher electrical conductivity and good electrocatalytic properties towards the electrooxidation of nitrite in a neutral medium than other nanomaterials. Eventually, Ag/Au/rGO NC’s confirmed the enhanced antibacterial against Gram-negative bacteria and dose dependent antifungal inhibitory activities against foodborne fungal pathogens of Fusarium graminearum, Alternaria alternata, and phytopathogenic fungus of Curvularia lunata and Sclerotinia sclerotiorum at the maximum tested conc. of 2 mg/mL, compared to other nanomaterials. From the result of zebrafish embryotoxicity (ZET), the highest toxicity was observed for AgNPs at 0.19 μg/mL. But in the case of Ag/Au/rGO NC’s the reduced toxicity was observed. Hence, the achieved results concluded the Ag/Au/rGO NC’s could be suitable for development of both as biomaterials for biomedical and effective sensors for environmental applications.

Amomum subulatum Fruit Extract Mediated Green Synthesis of Silver and Copper Oxide Nanoparticles: Synthesis, Characterization, Antibacterial and Anticancer Activities

This research presents a straightforward, effective, and eco-friendly method for the production of silver nanoparticles (AgNPs) and copper oxide nanoparticles (CuONPs) using the dried fruit of Amomum subulatum as a reducing, stabilizing, and capping agent. The formation of AgNPs and CuONPs is supported by the presence of a surface plasmon resonance band (SPR) at 440 nm for AgNPs and 245 nm for CuONPs. Additionally, the identification of specific biomolecules responsible for the synthesis of AgNPs and CuONPs was confirmed through FTIR spectra analysis. The Transmission electron microscope (TEM) images demonstrated that AgNPs and CuONPs had spherical shapes, with mean particle diameters of 20.6 nm and 24.7 nm, respectively. X-ray diffraction and selected area electron diffraction (SAED) analyses provided evidence of the crystalline nature of the synthesized AgNPs and CuONPs. Additionally, the presence of silver and copper elements was observed through energy-dispersive X-ray spectroscopy (EDS) analysis. Furthermore, the antibacterial activity of AgNPs was found to be superior to that of CuONPs against human pathogens such as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The cytotoxic activity of the biosynthesized nanoparticles (NPs) was evaluated in vitro against human cervical cells (HeLa) and human breast cells (MCF-7). In MCF-7 cells, the IC50 value for AgNPs was estimated to be 39.79 µg/mL, while that of CuONPs was 83.89 µg/mL. In HeLa cells, the IC50 value for AgNPs was 45.5 µg/mL, and for CuONPs, it was 97.07 µg/mL. For the first time, an eco-friendly method for the synthesis of AgNPs and CuONPs from fruit extract of Amomum subulatum has been discussed along with their comparative evaluation study. These results highlight the promising applications of the eco-friendly synthesized AgNPs and CuONPs as effective agents against microbial infections and potential candidates for cancer therapy.

Efficient degradation of 4-nitrophenol and colorimetric detection of Fe (III) by biogenic silver nanoparticles of Papiliotrema laurentii

In this study, novel biogenic silver nanoparticles have been developed involving a green method by a yeast strain, Papiliotrema laurentii (Y24) cell resuspension exudate. Synthesis conditions have been optimized and the produced nanomaterials have been characterized by DLS, Zeta Potential, FTIR, XRD, SEM, TEM to predict and analyse the particles. High crystallinity, irregular to cubical shape, and an average dimension of 20 nM of AgNPs were obtained from the characterization. Biogenic Y24-NPs were applied to reduce 4-Nitrophenol to 4-Aminophenol by catalytic activity (within 8 min). After 5 recycles, high reusability of Y24-NPs was observed (≥ 94%). Y24-NPs were further demonstrated for high selectivity and sensitivity towards Fe3＋ by colorimetric detection with the limit of 1.8 μM in the linear range of 5–150 μM. Additionally, the developed nanosensor has been tested for Fe3＋ ions in tap water samples. Therefore, Y24-NPs can be used for bioremediation with significant catalytic activity and reusability.

Green Synthesis of Gold and Silver Nanoparticles Using Invasive Alien Plant Parthenium hysterophorus and Their Antimicrobial and Antioxidant Activities

Due to the high energy demands and environmental hazards of physical and chemical methods, it is now essential to produce nanoparticles using plant sources as reducing and stabilizing agents. In this study, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were biosynthesized using an aqueous extract of Parthenium hysterophorus aerials as a reducing and stabilizing agent. The synthesized nanoparticles were characterized using UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and transmission electron Microscopy (TEM). UV–Vis spectroscopy indicates that the peaks of AgNPs and AuNPs are at 422 and 538 nm, respectively. The results of the DLS analysis showed that both Au and AgNPs are monodispersed and stable and have mean hydrodynamic sizes of 53.55 nm and 68.12 nm, respectively. According to an XRD analysis, the generated AgNPs and AuNPs are face-centered cubic crystals with average crystalline diameters of 33.4 nm and 30.5 nm, respectively. TEM image depicted that the synthesized NPs mainly have spherical shapes with particle size in the range of 3.41–14.5 nm for AuNPs and 5.57–26.3 nm for AgNPs. These biologically produced AuNPs and AgNPs were investigated for their antibacterial, antifungal, and antioxidant effects. Both AuNPs and AgNPs were found to strongly influence the growth of bacterial pathogens, with a maximum zone of 22.3 and 19.7 mm in Escherichia coli and a minimum zone of 11.7 and 10.3 mm in Salmonella enterica, respectively. The synthesized AuNPs and AgNPs reduce the numbers of viable fungi by 51.06% and 47.87%, respectively. The DPPH (2,2-diphenyl-1-picrylhydrazyl) assay revealed that the synthesized AuNPs and AgNPs have significant radical scavenging ability with 88.75% and 86.25% inhibition and 33.62 μg/mL and 42.86 μg/mL of IC50, respectively. Therefore, an aqueous extract of aerial parts of P. hysterophorus can be a suitable precursor for synthesizing AuNPs and AgNPs, with numerous applications. Due to their smaller size, AuNPs have better antimicrobial and antioxidant activities than AgNPs. This study supports the conservation by a utilization strategy of invasive alien plant species control and management (such as P. hysterophorus) for biodiversity conservation and environmental sustainability.

Advanced polymeric metal/metal oxide bionanocomposite using seaweed Laurencia dendroidea extract for antiprotozoal, anticancer, and photocatalytic applications.

Biosynthesized nanoparticles are gaining popularity due to their distinctive biological applications as well as bioactive secondary metabolites from natural products that contribute in green synthesis. This study reports a facile, ecofriendly, reliable, and cost-effective synthesis of silver nanoparticles (AgNPs), copper oxide nanoparticles (CuONPs), and polymeric PVP-silver-copper oxide nanocomposite using ethanol extract of seaweed Laurencia dendroidea and were evaluated for antiprotozoal, anticancer and photocatalytic potential. The nanostructures of the AgNPs, CuONPs, and polymeric PVP-Ag-CuO nanocomposite were confirmed by different spectroscopic and microscopic procedures. The UV-vis spectrum displayed distinct absorption peaks at 440, 350, and 470 nm for AgNPs, CuONPs, and polymeric Ag-CuO nanocomposite, respectively. The average particles size of the formed AgNPs, CuONPs, and Ag-CuO nanocomposite was 25, 28, and 30 nm, respectively with zeta potential values -31.7 ± 0.6 mV, -17.6 ± 4.2 mV, and -22.9 ± 4.45 mV. The microscopic investigation of biosynthesized nanomaterials revealed a spherical morphological shape with average crystallite sizes of 17.56 nm (AgNPs), 18.21 nm (CuONPs), and 25.46 nm (PVP-Ag-CuO nanocomposite). The antiprotozoal potential of green synthesized nanomaterials was examined against Leishmania amazonensis and Trypanosoma cruzi parasites. The polymeric PVP-Ag-CuO nanocomposite exerted the highest antiprotozoal effect with IC50 values of 17.32 ± 1.5 and 17.48 ± 4.2 µM, in contrast to AgNPs and CuONPs. The anticancer potential of AgNPs, CuONPs, and polymeric PVP-Ag-CuO nanocomposite against HepG2 cancer cell lines revealed that all the nanomaterials were effective and the highest anticancer potential was displayed by PVP-Ag-CuO nanocomposite with IC50 values 91.34 µg mL-1 at 200 µg mL-1 concentration. Additionally, PVP-Ag-CuO nanocomposite showed strong photocatalytic effect. Overall, this study suggested that the biogenic synthesized nanomaterials AgNPs, CuONPs, and polymeric PVP-Ag-CuO nanocomposite using ethanol extract of seaweed L. dendroidea possesses promising antiprotozoal anticancer and photocatalytic effect and could be further exploited for the development of antiprotozoal and anticancer therapeutics agents.

Ultra-Small Silver Nanoparticles: A Sustainable Green Synthesis Approach for Antibacterial Activity

The present study centers on the synthesis of ultra-small silver nanoparticles (AgNPs) with antibacterial properties using citrus peel residues (orange, lemon, and grapefruit) as reducing and stabilizing agents, and on assessing their antibacterial activity against multidrug-resistant clinical Staphylococcus aureus. The synthesized AgNPs were analyzed by various techniques, including UV-Vis spectroscopy, SAED, TEM, XRD, FTIR, and Raman. The results demonstrate the formation of ultra-small, monodisperse, quasi-spherical AgNPs with an average particle size of 2.42 nm for AgNPs produced with mixed extracts. XRD analysis indicated that the AgNPs have a crystal size of 9.71 to 16.23 nm. The AgNPs exhibited potent inhibitory activity against resistant S. aureus, with a minimum inhibitory concentration (MIC) of 15.625 to 62.50 ppm. The findings suggest that the ultra-small nanometer size of the AgNPs could be attributed to the synthesis method that employs ambient conditions and the presence of polyphenolic compounds from citrus peel. Consequently, AgNPs obtained through sustainable green synthesis hold significant potential in combating clinical multi-resistant bacterial strains that are challenging to treat and eradicate. This approach also contributes to the revaluation of citrus residues in the region, which is an ongoing environmental issue today.

Green Synthesis of Silver Nanoparticles Using Rhazya stricta Decne Extracts and Their Anti-Microbial and Anti-Oxidant Activities

The present study shows the synthesis of silver nanoparticles (Ag NPs) using a methanolic and aqueous extract of R. stricta. UV–visible spectroscopy, energy-dispersive X-ray diffraction (EDX), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FTIR) techniques were used to further characterize the Ag NPs. UV–visible spectra give surface Plasmon resonance (SPR) at 490–560 nm for Ag NPs. The existence of various functional groups existing in biomolecules capping the nanoparticles is indicated by the FTIR spectrum. The average size of Ag NPs is 20–35 nm, while the shape is spherical, as confirmed by FESEM. The plant extract and Ag NPs were evaluated against their antioxidant, antibacterial (Staphylococcus aureus, E. coli, and Salmonella typhi), and antifungal activities (Trichophyton longifusis, Candida albican, and Fusarium solani), where the Ag NPs exhibited superior activity versus the plant extract. The inhibitory effect of NPs against the tested strain was more effective as compared to the crude extract of R. stricta.

Bioynthesis of silver nanoparticles using Dunaliella salina and its antibacterial applications

In this study, an aqueous extract of Dunaliella salina was used to reduce silver nitrate and create silver nanoparticles (AgNPs). Silver nanoparticles were created as soon as silver particles made in contact with the microalgae extract, showing the speedy preparation process. The microalgae extract was prepared and used for biosynthesis of silver nanoparticles. Synthesized nanoparticles were characterized using UV–Vis, SEM-EDX, XRD and FTIR analysis. Antibacterial assays were performed using disc-diffusion method. A peak at 454 nm was found in the UV–Vis range of the aqueous media containing silver particles, which was related to the plasmon absorbance of AgNPs. Scanning electron microscope (SEM) demonstrated size of 35 nm of AgNPs. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of AgNPs, which revealed a solid flag in the silver region. X-ray diffraction (XRD) confirmed the formation of crystalline nanoparticles. The presence of functional groups in AgNPs was confirmed using Fourier transform infrared (FTIR) analysis. Antibacterial property of synthesized nanomaterials was also found to have a possible antibacterial effects on Escherichia coli, Bacillus subtilis, as well as Enterobacter tobbaci. Thus, silver nanoparticles were biosynthesized using Dunaliella salina microalgae extract and tested for antibacterial effects.