Metallic Silver Nanoparticles Research Articles

Plasmonic Surface of Metallic Gold and Silver Nanoparticles Induced Fluorescence Quenching of Meso-Terakis (4-Sulfonatophenyl) Porphyrin (TPPS) and Theoretical–Experimental Comparable

Colloidal metallic nanoparticles have attracted a lot of interest in the last two decades owing to their simple synthesis and fascinating optical properties. In this manuscript, a study of the effect of both gold nanoparticles (Au NPs) and silver nanoparticles (Ag NPs) on the fluorescence emission (FE) of TPPS has been investigated utilizing steady-state fluorescence spectroscopy and UV–Vis spectrophotometry. From the observed electronic absorption spectra, there is no evidence of the ground state interaction between metallic Au NPs or Ag NPs with TPPS. On the other side, the FE spectra of TPPS have been quenched by both Ag and Au NPs. Via applying quenching calculations, Ag NPs showed only traditional static fluorescence quenching of TPPS with linear Stern–Volmer (SV) plots. On the contrary, quenching of TPPS emission by Au NPs shows composed models. One model is the sphere of action static quenching model that prevails at high quencher concentrations leading to non-linear SV plots with positive deviation. However, at low Au NPs concentrations, traditional dynamic quenching occurs with linear SV plots. The quantum calculations for TPPS structure have been obtained using Gaussian 09 software: in which the TPPS optimized molecular structure was achieved using DFT/B3LYP/6-311G (d) in a gaseous state. Also, the calculated electronic absorption spectra for the same molecule in water as a solvent are obtained using TD/M06/6-311G + + (2d, 2p). Furthermore, the theoretical and experimental results comparable to UV–Vis spectra have been investigated.

Nanostructured hexagonal BN coating-supported silver and iron oxide nanoparticles and related bactericidal and fungicidal activities

The history of mankind is inextricably linked with the fight against infections, and today this problem is even more urgent. To address this important issue, we deposited h-BN coatings decorated with ultrafine metallic silver or iron oxide nanoparticles (NPs). The coatings release metal ions in a concentration dependent manner. Fe/h-BN coatings at a minimum inhibitory concentration (MIC) of iron oxide NPs (74 µg/cm2), effectively suppress the growth of Escherichia coli K-261 and U20, Staphylococcus aureus MW2 and 839, and Streptococcus pneumoniae ATCC33400 bacterial strains and Candida parapsilosis ATCC90018 fungus after 24 h. Enhanced bactericidal and fungicidal activities of Fe-rich samples is attributed to generation of high amount of ROS. Ag/h-BN materials at MIC of Ag equal to 12 µg/cm2, completely inactivate Escherichia coli K-261 and U20, and Staphylococcus aureus MW2 and 839 strains after 24 h. Sample with 25 μg/cm2 of Ag NPs kill all Escherichia coli K-261 and U20, and Staphylococcus aureus MW2 cells after 3 h and effectively inhibit the growth of Staphylococcus aureus ATCC25923, Candida parapsilosis ATCC90018, Escherichia coli C600, Candida auris CBS10913, and Streptococcus pneumoniae ATCC33400. These results are important for the further development of nanostructured films with a wide spectrum of activity against various pathogens.

The green & eco-friendly biosynthesized biocompatible metallic silver nanoparticles for anti-bacterial and anti-biofilm efficacy

The green & eco-friendly biosynthesized biocompatible metallic silver nanoparticles for anti-bacterial and anti-biofilm efficacy

New approach for the synthesis of Ag3PO4-graphene photocatalysts

A facile and effective plasma sputtering method for the preparation of a visible light active photocatalyst - rhombic dodecahedral silver phosphate Ag3PO4 covered with nanographene (Ag3PO4-GR) with improved stability has been developed. Proposed method allows for the usage of readily available materials for nanographene sputtering and for easy scaling-up. The stability improvement, confirmed by visible light-induced phenol degradation experiment, could be attributed to the synergistic effect of the silver phosphate particles and graphene material allowing for migration of metallic silver nanoparticles from semiconductor's surface to graphene body keeping the semiconductors surface “silver free”. Also due to its conductive properties, nanographene may additionally be preventing electron-hole recombination and metallic silver formation.

In situ deposition of Ag nanoparticles onto PE/rGO hybrids for the dip-catalytic hydrogenation of 4-nitrophenol into 4-aminophenol

ABSTRACT This study was focused on the design and development of a new heterogeneous catalyst based on polyester (PE) fabric modified with graphene oxide nanosheets decorated with silver metallic nanoparticles (PE-rGO/Ag0), using a simple, easy, and effective approach. PE fabrics were coated by sonication with graphene oxide (GO) nanosheets followed by in situ deposition and reduction of silver nanoparticles over the GO surface, covering the PE fabric and producing PE-rGO/Ag0. The crystalline structure, surface morphology and chemical characteristics of the synthesised materials were identified by X-ray diffraction spectroscopy, scanning and transmission electron microscopy analyses (SEM and TEM) and by Fourier-transform infrared spectroscopy (FTIR), respectively. The catalytic performance of the prepared PE-rGO/Ag0 was assessed during the hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride (NaBH4). Experimental results indicate that PE-rGO/Ag0 with a surface of 6 cm2 (3x2 cm) showed the highest catalytic activity with an apparent reaction rate constant (Kapp) of 0.65 min−1. In addition, PE-rGO/Ag0 activity resulted to be comparable and significantly higher than previously reported values of silver-based catalysts. Remarkable stability values were achieved during different operating cycles without significant degradation in the catalytic activity, suggesting that PE-rGO/Ag0 can be used as a strong candidate in long-lasting chemical catalytic processes.

Polyphenol-Capped Biogenic Synthesis of Noble Metallic Silver Nanoparticles for Antifungal Activity against Candida auris.

In terms of reduced toxicity, the biologically inspired green synthesis of nanoparticles has emerged as a promising alternative to chemically fabricated nanoparticles. The use of a highly stable, biocompatible, and environmentally friendly aqueous extract of Cynara cardunculus as a reducing and capping agent in this study demonstrated the possibility of green manufacturing of silver nanoparticles (CC-AgNPs). UV–visible spectroscopy validated the development of CC-AgNPs, indicating the surface plasmon resonance (SPR) λmax band at 438 nm. The band gap of CC-AgNPs was found to be 2.26 eV. SEM and TEM analysis examined the surface morphology of CC-AgNPs, and micrographs revealed that the nanoparticles were spherical. The crystallinity, crystallite size, and phase purity of as-prepared nanoparticles were confirmed using XRD analysis, and it was confirmed that the CC-AgNPs were a face-centered cubic (fcc) crystalline-structured material. Furthermore, the role of active functional groups involved in the reduction and surface capping of CC-AgNPs was revealed using the Fourier transform infrared (FTIR) spectroscopic technique. CC-AgNPs were mostly spherical and monodispersed, with an average size of 26.89 nm, and were shown to be stable for a longer period without any noticeable change at room temperature. Further, we checked the antifungal mechanism of CC-AgNPs against C. auris MRL6057. The minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) were 50.0 µg/mL and 100.0 µg/mL respectively. The cell count and viability assay confirmed the fungicidal potential of CC-AgNPs. Further, the analysis showed that CC-AgNPs could induce apoptosis and G2/M phase cell cycle arrest in C. auris MRL6057. Our results also suggest that the CC-AgNPs were responsible for the induction of mitochondrial toxicity. TUNEL assay results revealed that higher concentrations of CC-AgNPs could cause DNA fragmentation. Therefore, the present study suggested that CC-AgNPs hold the capacity for antifungal drug development against C. auris infections.

Bulky Thiolate-Protected Silver Nanocluster Ag 213 (Adm-S) 44 Cl 33 with Excellent Electrocatalytic Performance toward Oxygen Reduction

Bulky Thiolate-Protected Silver Nanocluster Ag ₂₁₃ (Adm-S) ₄₄ Cl ₃₃ with Excellent Electrocatalytic Performance toward Oxygen Reduction

Enhanced energy transfer from diolefinic laser dyes to meso-tetrakis (4-sulfonatophenyl) porphyrin immobilized on silver nanoparticles: DFT, TD-DFT and spectroscopic studies

Porphyrin derivatives are known singlet oxygen sensitizers in photodynamic therapy (PDT). Energy transfer from a class of diolefinic laser dyes (DOLDs) as energy donors to the sodium salt of meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) as the accepter of energy would extend the range of photon harvesting down to the UV-region. Energy transfer was substantially enhanced in the presence of metallic silver nanoparticles (AgNPs), as revealed by steady-state emission spectroscopy, lifetimes, and quantum mechanics. DOLDs under investigation are 2,5-distyrylpyrazine (DSP), 1,4-bis (β-pyridyl-2 vinyl) benzene (P2VB), and 1,4 bis (2-methylstyryl) benzene (MSB) as efficient donors of intense absorption in the UV-region. AgNPs enhance the rate of energy transfer from DOLDs to TPPS via bringing donor and acceptor into close- proximity with a concomitant increase in dipole–dipole interaction between excited state donor and ground-state acceptor. The DOLDs molecular structures were optimized using the DFT/CAM-B3LYP/6-311G++ (d, p) level of theory. The calculated electronic absorption spectra for the studied DOLDs in the gaseous phase and methanol solvent were studied using the time-dependent density functional theory (TD-DFT) at M06-2X/6-311G++ (2d,2p) level. The calculated absorption/emission spectra for DSP laser dye in methanol are obtained at the TD/ M06-2X/6-311G++(2d, 2p) method. Notably, all theoretical results of the molecular structures under study highly agreed with the practical optical results. Energy transfer rate constants (kET) amid energy donor/acceptor pairs were determined by Stern-Volmer constants (KSV) and donors' lifetime measurements. The KSV values indicate an enhanced Fluorescence Resonance Energy Transfer (FRET) efficiencies in the presence of negatively charged AgNPs. The critical transfer distances Ro were determined from the spectral overlap between the emission spectrum of donor and absorption spectrum of TTPS. These outcomes propose the application of designed metal-enhanced FRET for energy-transfer-based assays and photodynamic therapy (PDT) applications.

1,4-bis[β-(2-benzoxazoly1) vinyl] benzene (BBVB) laser dye and sodium salt of meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS); spectroscopic investigation and DFT, NBO and TD-DFT calculations

Excitation energy transfer (ET) from 1,4-bis[β-(2-benzoxazoly1) vinyl] benzene as a donor to sodium salt of meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) as an acceptor was investigated in the absence and presence of metallic silver nanoparticles (Ag NPs). The emission intensities and Stern –Volmer constants (KSV) of the ET processes were calculated in methanol (MeOH) and 40% ethylene glycol (EG) as 5.87 × 104 M−1 and 6.27 × 104 M−1, respectively. KSV value in the presence of Ag NPs was 1.028 × 105 M−1 in methanol, much higher than in absence of NPs. This is attributed to the role of Ag NPs in increasing the strength of the donor–acceptor interactions. These results denote the use of Ag NPs for measuring the proximity of large biomolecules and ET-based assays. Also, the critical ET distance Ro was calculated as 36 Å. This magnitude is higher than the common value of 10 Å for the collisional ET mechanism. This high Ro value indicates the underlying mechanism as long-range dipole–dipole interaction. The BBVB, TPPS, and BBVB/TPPS molecular structures (MSs) were optimized using the DFT/ B3LYP/6-311G (d) method for the quantum calculations. The calculated electronic UV–Vis absorption spectra for BBVB and BBVB/TPPS MSs in MeOH were examined by the time-dependent density functional theory (TD-DFT) at CAM-B3LYP/6-311G++(3d,3p) level. Interestingly, all theoretical results of BBVB and BBVB/TPPS molecules were highly matched with the experimental results. Furthermore, the Natural Bond Orbital (NBO) analyses for BBVB and BBVB/TPPS MSs were obtained using the B3LYP/6-311G(d) level of theory.

Synthesis and Characterization of Ag/ZnO Nanoparticles for Bacteria Disinfection in Water.

In this study, two green synthesis routes were used for the synthesis of Ag/ZnO nanoparticles, using cassava starch as a simple and low-cost effective fuel and Aloe vera as a reducing and stabilizing agent. The Ag/ZnO nanoparticles were characterized and used for bacterial disinfection of lake water contaminated with Escherichia coli (E. coli). Characterization indicated the formation of a face-centered cubic structure of metallic silver nanoparticles with no insertion of Ag into the ZnO hexagonal wurtzite structure. Physicochemical and bacteriological analyses described in “Standard Methods for the Examination of Water and Wastewater” were used to evaluate the efficiency of the treatment. In comparison to pure ZnO, the synthesized Ag/ZnO nanoparticles showed high efficiencies against Escherichia coli (E. coli) and general coliforms present in the lake water. These pathogens were absent after treatment using Ag/ZnO nanoparticles. The results indicate that Ag/ZnO nanoparticles synthesized via green chemistry are a promising candidate for the treatment of wastewaters contaminated by bacteria, due to their facile preparation, low-cost synthesis, and disinfection efficiency.

Recent Developments for the Detection of Escherichia Coli Biosensors Based on Nano-Objects—A Review

Advances in nanotechnology have made it possible in recent years to develop strategies for rapid and sensitive detection of pathogenic bacteria using new nanomaterials and the development of electronic nano-sensors. The detection of bacteria still faces problems such as long analysis time and complexity of the process. An alternative method is the use of biosensors, which combines a biological recognition mechanism with a physical transduction technique. Thus, a number of methods and manufacturing technologies have been developed in order to achieve performance in sensitivity, detection limit, label-free detection or real-time analysis. This review aims to focus on the state of the art of biosensors for the recognition elements of Escherichia coli in label-free biosensors with a particular focus on the beneficial use of nanomaterials and nano-objects for detection. Among the recent related biosensors based on nano-objects for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E. coli</i> detection, the technologies and measurement techniques are detailed by comparing their performances detection in terms of concentration range and detection limit. Detection becomes more sensitive and more flexible using nanoparticles as markers, and real-time electrical detection methods are dominant in comparison with optical ones. The lowest detection limit can be achieved for sensors based on metal (gold or silver nanoparticles) with optical detection techniques in contrast with electrical detection methods using measurement conductance.

Design of a new label free active biosensor based on metallic nanoparticles-doped graphene nanodisk platform

The advantage of graphene nanomaterial to support strong plasmonic resonances in the THz frequency range makes it an ideal candidate in biosensing field where the ability of detecting molecules is becoming essential to improve the quality of human life. In this paper, a theoretical study of plasmon nanosensor based on silver metallic nanoparticles (Ag MNPs) placed near the surface of graphene nanodisk (GND) for blood components detection is analyzed and then the results are presented. The exploited nonlinear Kerr effect shows that the sensitivity (Se) is equal to 472 (nm/RIU) in THz frequency range while the selectivity (θ) is around 19.6 RIU−1. The proposed biosensor is characterized by a wide linear range sensor between 0.02mM–0.054 mM and a limit of detection (LoD) around 0.018 mM. It is mentioned that the chemical potential (μ) and the temperature (T) of graphene nanodisk essentially control the sensitivity of the proposed biosensor which represents a fundamental feature in optical sensor processing and leverages the CMOS compatibility necessary for various biological compounds detection.

Sustainable biosynthesis of metallic silver nanoparticles using barberry phenolic extract: Optimization and evaluation of photocatalytic, in vitro cytotoxicity, and antibacterial activities against multidrug-resistant bacteria

The contamination of water resources by various pollutants such as organometallic compounds and organic pollution is one of the major challenges in all over the world. In the past few years, the cost-effective and eco-friendly synthesis of nanoparticles using environmentally friendly approaches have been developed among scientists. In this research, we synthesized silver nanoparticles by the rapid, inexpensive and eco-friendly process using Berberis vulgaris (B. vulgaris; BV@AgNPs) extract, for the first time. Optimized product was obtained by controlling the molar ratio of raw materials, temperature, contact time, and pH of the reaction. The biosynthesized BV@AgNPs were used as a catalytic, antibacterial, and anticancer agents. The obtained oval and spherical-like BV@AgNPs were characterized by different analytical techniques, including TEM, FESEM, UV–Vis, EDX, XRD, and FT-IR. Characterization of the BV@AgNPs showed the average crystalline size of 45–60 nm and spherical morphology with only few agglomerated particles. The photocatalytic efficiency of BV@AgNPs was determined by degradation of methyl orange in various concentrations of nanocatalyst under sunlight irradiation. The BV@AgNPs exhibited high photocatalytic degradation (97.82%) in short time. The synthesized BV@AgNPs was tested for antibacterial activity using the Mueller-Hinton broth method. Furthermore, the antibacterial effect of the synthesized BV@AgNPs was studied against seven clinically isolated multidrug-resistant bacteria. The MIC value of BV@AgNPs against P. mirabilis (PM-2), E. coli (EC-2), E. faecalis (EF-2), S. aureus (SA-2), A. baumannii (AB-2), P. aeruginosa (PA-2), and K. pneumonia (KP-2) were 1.56, 0.4, 0.8, 1.56, 0.5, 0.4, and 6.25 µg/mL. Determination of the cytotoxic effect of the biosynthesized BV@AgNPs were carried out using two types of cell lines, human gastric cancer cell line (AGS, IC50 = 3.16 µg/mL) and human breast cancer cell line (MCF-7; IC50 = 9.37 µg/mL). These findings suggested that B. vulgaris extract mediated silver nanoparticles can be used in various fields including industrial wastewater treatment and biomedical.

Influence of elemental composition on structural, thermal and hydration behavior of gold-silver bimetallic nanoparticles.

In this study, molecular dynamics simulations (MDs) have been employed to explore the influence of elemental composition on the structural, thermal, and hydration behavior of the core-shell gold-silver bimetallic nanoparticles with three different concentrations Au135Ag114, Au87Ag162, and Au55Ag194. The pure gold and silver metal nanoparticles have also been studied for the sake of comparison. The calculated cohesive and formation energy values reveal the enhancement in the stability of gold-silver bimetallic nanoparticles with the increase in the concentration of gold. The specific heat capacity value of the bimetallic gold-silver nanoparticles has been found to increase linearly with the concentration of silver. This suggests that the specific heat capacity value of the gold-silver bimetallic nanoparticles may be improved by raising their silver concentration. The enhancement of specific heat capacity value with respect to the concentration of silver may be attributed to the enhanced phonon density. There is no significant difference in the computed hydration shell and water residence time of the gold-silver bimetallic nanoparticles with respect to their mixing ratio. The obtained stable structure, tunable specific heat capacity values, and the predicted hydration properties of the gold-silver bimetallic nanoparticles may be harnessed for their technological and biological applications.

Research on sulfate bacteriostatic effect of some metal nanos

Sulfate-reducing bacteria (Desulfomicrobium baculatum) is a group of anaerobic bacteria capable of producing H2S gas, which sours crude oil, corrodes metal equipment, pipeline systems, and even forms biofilms that cause blockages reservoir, reducing the reception capacity of pumped water in oil and gas exploitation. Currently, the biocides are mainly aldehydes or cyclic amines combined with cationic active substances, which are very toxic to humans and the environment. The development of materials technology has created new nano-sized materials that are capable of replacing traditional biocides and are environmentally friendly. This study has shown that silver and copper metal nanoparticles with an average size of 50 nm and concentration from 500 ppm can inhibit and kill both sulfate-reducing bacteria strains swimming and adhering in the water at normal and high temperature conditions.

Silver nanoparticle incorporation into flexible polyamide 12 membranes.

To meet the demands of the market and society, the development of structured polymeric materials for application in the medical field is constantly increasing. Over the last decades, metallic silver nanoparticles have been explored due to their antimicrobial action. Here, we aimed to incorporate metallic silver nanoparticles into polymeric pieces obtained by additive manufacture via a chemical route involving silver nitrate and sodium borohydride. Polyamide 12 membranes were obtained by selective laser sintering, which was followed by washing, pretreatment, and functionalization with the alkoxides tetraethylorthosilicate and 3-aminopropyl tetraethoxysilane. For nanoparticle preparation and incorporation, a chemical route was tested under different conditions. The samples were characterized by techniques, such as X-ray diffraction, ultraviolet-visible spectroscopy, and infrared vibrational spectroscopy. Nanoparticle formation and incorporation into the polyamide 12 membranes were demonstrated by the absorbance band at 420 nm, which indicated that the particles measured between 10 and 50 nm in size; by the X-ray diffraction peaks at 2θ = 38, 44, and 64°, which are typical of crystalline silver; and by vibrational spectroscopy, which evidenced that the nanoparticles interacted with the polyamide 12 nitrogen groups. Polyamide 12 membranes containing metallic silver nanoparticles have promising biomedical applications as antimicrobial wound dressings associated with drug carriers.

Green Fabrication of Silver Nanoparticles using Euphorbia serpens Kunth Aqueous Extract, Their Characterization, and Investigation of Its In Vitro Antioxidative, Antimicrobial, Insecticidal, and Cytotoxic Activities.

The silver nanoparticles (AgNPs) were synthesized via green synthesis approach using Euporbia serpens Kunth aqueous extract. The synthesized AgNPs were characterized by UV-visible spectroscopy and Furrier Transformer Infra-Red spectroscopy to justify the reduction and stabilization of AgNPs from its precursors. AgNPs characteristic absorption peak was observed at 420 nm in the UV-visible spectrum. The SEM and TEM analysis demonstrated the spherical shape of the synthesized nanoparticles with particle sizes ranging from 30 nm to 80 nm. FTIR transmission bands at 2920 cm−1, 1639 cm−1, 1410 cm−1, 3290 cm−1, and 1085 cm−1 were attributed to C-H, C=O, C-C, N-H, and C-N functional groups, respectively. XRD peaks could be attributed to (111), (200), (220), and (311) crystalline plane of the faced-centered cube (FCC) crystalline structure of the metallic silver nanoparticles. The AgNPs showed good antibacterial activity against all the tested bacteria at each concentration. The particles were found to be more active against Escherichia coli (E. coli) with 20 ± 06 mm and Salmonella typhi (S. typhi) with 18 ± 0.5 mm zone of inhibition in reference to standard antibiotic amoxicillin with 23 ± 0.3 mm and 20 ± 0.4 mm zone of inhibition, respectively. Moderate antifungal activities were observed against Candida albicans (C. albicans) and Alternaria alternata (A. alternata) with zone of inhibitions 16.5 mm and 15 mm, respectively, compared to the standard with 23 mm of inhibition. Insignificant antifungal inhibition of 7.5 mm was observed against Fusarium gramium (F. gramium). All the tested concentrations of AgNPs showed comparable % RSA with the standard reference ascorbic acid in the range sixty percent to seventy five percent. The percent motility at 3 hours postincubation showed quick response and most Tetramorium caespitum were found deceased or paralyzed. Similarly, the percent mortality showed a linear response at concentration and time. It was observed that 1 μg/mL to 2 μg/mL concentration of AgNPs displayed a significant cytotoxic activity against Artemia salina with LD50 of 5.37 and 5.82, respectively.

BIOCATALYTIC EFFECT OF Simarouba glauca LEAF PHYTOCHEMICALS ON BIOLOGICALLY ACTIVE SILVER NANOPARTICLES YIELD AND ABTS ANTIOXIDANT ACTIVITY: GREEN SYNTHESIS

Green synthesis of gold, copper, and silver metal nanoparticles is currently growing research due to different medical applications. Necessary natural human health-protecting components can be derived using nanobiotechnology using plant extracts in biodiversity enriched countries. Silver nanoparticles have shown various biological applications such as antimicrobial, anticancer, and antidiabetic activities. Hence, this work studied the yield and antioxidant activity of silver nanoparticles derived from various solvent extracts of Simarouba glauca leaflike methanol, ethanol, chloroform, ethyl acetate, and water. The derived silver nanoparticles of various extracts were characterized by absorption and vibrational spectra. Out of the five extracts, high yield silver nanoparticles surface morphology was inspected by scanning electron microscope. Also, the prepared silver nanoparticle’s antioxidant activity was examined using the 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid assay protocol, and the results were compared for future work. From the results, this work observed that the silver nanoparticles of ethanol crude exposed 72% yield and 39% yield obtained from chloroform extract. The silver nanoparticles of methanol crude showed good antioxidant activity (IC50 = 16.59μg/ml) when compared to the other extract nanoparticles due to the phytochemicals concentration difference.

Sustainable green synthesis of silver nanoparticles using Sambucus ebulus phenolic extract (AgNPs@SEE): Optimization and assessment of photocatalytic degradation of methyl orange and their in vitro antibacterial and anticancer activity

The biogenic approach in the synthesis of nanoparticles provides an efficient alternative to the chemical synthesis system. Furthermore, the ecofriendly synthesis of metallic nanoparticles is developing rapidly due to its wide applications in sciences. In this research, metallic silver nanoparticles (AgNPs) were biosynthesized using Sambucus ebulus ( S. ebulus ; AgNPs@ SEE ) extract for the evaluation of efficient antibacterial, anticancer, and photocatalyst activities. The reaction parameters including temperatures, contact time, and AgNO 3 concentration were discussed and optimized. The optimized nanoparticles (AgNPs@ SEE) showed cubic structure, spherical morphology with the average size of 35–50 nm. The photocatalytic performance of AgNPs was assessed by degradation of methyl orange at different concentrations of AgNPs@ SEE (10 and 15 µl) under sun-light irradiation. About 95.89% of the pollutant was degraded (after 11 min), when 10 μl of nanocatalyst used. Also, the degradation of contaminant increased (about 95.47% after 7 min) by increasing the nanoparticle concentration to 20 μl. All in all, the results showed that the percentage of pollutant degradation increased with increasing the concentration of nanocatalyst. Furthermore, anticancer activity of AgNPs@ SEE on human cancer cell lines (AGS and MCF-7), and antibacterial activity on both Gram-positive and Gram-negative microorganisms were studied. The synthesized AgNPs@ SEE exhibited superior performance on cancer cell lines and effective antibacterial properties against Gram-positive microorganisms (like MIC value of 1.5 µg/ml for S. aureus ) than Gram-negative microorganisms. All these investigations revealed that silver nanoparticles synthesized by natural extract have the potential to use as low-cost and efficient nanoparticles for environmental and biomedical applications.

The Green Synthesıs of Sılver and Selenıum Nanopartıcles usıng the Plant Stellarıa Medıa (L.) Vıll

Currently, the interest in the synthesis of metallic nanoparticles has increased a lot because these systems are suitable to be used in distinct fields such as medical, pharmaceutical, agricultural, environmental protection, etc. Their synthesis can be done using different agents such as bacteria, fungi, and yeasts or using plant extracts and fresh plants. This paper aims to synthesize metallic silver (AgNPs) and selenium (SeNPs) nanoparticles using the fresh plant Stellaria media (L.) Vill (SM)