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In recent years, there has been an increasing interest in the green synthesis of metallic nanoparticles, mostly because of the evident limitations associated with chemical and physical methods. Green synthesis, commonly referred to as "biogenic synthesis," is seen as an alternative approach to produce AgNPs (silver nanoparticles). The current work focuses on the use of Asterarcys sp. (microalga) for biological reduction of AgNO3 to produce AgNPs. The optimal parameters for the reduction of AgNPs were determined as molarity of 3 mM for AgNO3 and an incubation duration of 24 h at pH 9, using a 20:80 ratio of algal extract to AgNO3. The biosynthesized Ast-AgNPs were characterised using ultraviolet–visible spectroscopy (UV–Vis), zeta potential, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) patterns. The nanoparticles exhibited their highest absorption in the UV–visible spectra at 425 nm. The X-ray diffraction (XRD) investigation indicated the presence of characteristic peaks at certain angles: 38.30° (1 1 1), 44.40° (2 0 0), 64.64° (2 2 0), and 77.59° (3 1 1) according to the JCPDS file No. 04-0783. Based on SEM and TEM, the Ast-AgNPs had an average size of 35 nm and 52 nm, respectively. The zeta potential was determined to be − 20.8 mV, indicating their stability. The highest antibacterial effectiveness is shown against Staphylococcus aureus, with a zone of inhibition of 25.66 ± 1.52 mm at 250 μL/mL conc. of Ast-AgNPs. Likewise, Ast-AgNPs significantly suppressed the growth of Fusarium sp. and Curvularia sp. by 78.22% and 85.05%, respectively, at 150 μL/mL conc. of Ast-AgNPs. In addition, the Ast-AgNPs exhibited significant photocatalytic activity in degrading methylene blue (MB), achieving an 88.59% degradation in 120 min, revealing multiple downstream applications of Ast-AgNPs. [ABSTRACT FROM AUTHOR]

Background: Recently, researchers are focusing on creating new tools to combat the antibiotic resistant bacteria and malignancy issues, which pose significant threats to humanity. Biosynthesized silver nanoparticles (AgNPs) are thought to be a potential solution to these issues. The biosynthesis method, known for its environmentally friendly and cost-effective characteristics, can produce small-sized AgNPs with antimicrobial and anticancer properties. In this study, AgNPs were bio-fabricated from the distilled water and methanolic extracts of Viburnum grandiflorum leaves. Physio-chemical characterization of the bio-fabricated AgNPs was conducted using UV-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis. Results: AgNPs produced from the methanol extract were smaller in size (12.28 nm) compared to those from the aqueous extract (17.77 nm). The bioengineered AgNPs exhibited a circular shape with a crystalline nature. These biosynthesized AgNPs demonstrated excellent bactericidal activity against both gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. Highest antibacterial activity was observed with the methanol extract against P. aeruginosa (14.66 ± 0.74 mm). AgNPs from the methanol extract also displayed the highest antioxidant activity, with an IC50 value of 188.00 ± 2.67 μg/mL against 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, AgNPs exhibited notable cytotoxic activity against Rhabdomyosarcoma cell line (RD cell) of human muscle cancer cell. The IC50 values calculated from the MTT assay were 26.28 ± 1.58 and 21.49 ± 1.44 μg/mL for AgNPs synthesized from aqueous and methanol extracts, respectively. Conclusion: The methanol extract of V. grandiflorum leaves demonstrates significant potential for synthesizing AgNPs with effective antibacterial, antioxidant, and anticancer actions, making them applicable in various biomedical applications. [ABSTRACT FROM AUTHOR]

This study marks a pioneering effort in utilizing Vachellia tortilis subsp. raddiana (Savi) Kyal. & Boatwr., (commonly known as acacia raddiana) leaves as both a reducing and stabilizing agent in the green "eco-friendly" synthesis of silver nanoparticles (AgNPs). The research aimed to optimize the AgNPs synthesis process by investigating the influence of pH, temperature, extract volume, and contact time on both the reaction rate and the resulting AgNPs' morphology as well as discuss the potential of AgNPs in detecting some heavy metals. Various characterization methods, such as UV–vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), Zeta sizer, EDAX, and transmitting electron microscopy (TEM), were used to thoroughly analyze the properties of the synthesized AgNPs. The XRD results verified the successful production of AgNPs with a crystallite size between 20 to 30 nm. SEM and TEM analyses revealed that the AgNPs are primarily spherical and rod-shaped, with sizes ranging from 8 to 41 nm. Significantly, the synthesis rate of AgNPs was notably higher in basic conditions (pH 10) at 70 °C. These results underscore the effectiveness of acacia raddiana as a source for sustainable AgNPs synthesis. The study also examined the AgNPs' ability to detect various heavy metal ions colorimetrically, including Hg2+, Cu2+, Pb2+, and Co2+. UV–Vis spectroscopy proved useful for this purpose. The color of AgNPs shifts from brownish-yellow to pale yellow, colorless, pale red, and reddish yellow when detecting Cu2+, Hg2+, Co2+, and Pb2+ ions, respectively. This change results in an alteration of the AgNPs' absorbance band, vanishing with Hg2+ and shifting from 423 to 352 nm, 438 nm, and 429 nm for Cu2+, Co2+, and Pb2+ ions, respectively. The AgNPs showed high sensitivity, with detection limits of 1.322 × 10–5 M, 1.37 × 10–7 M, 1.63 × 10–5 M, and 1.34 × 10–4 M for Hg2+, Cu2+, Pb2+, and Co2+, respectively. This study highlights the potential of using acacia raddiana for the eco-friendly synthesis of AgNPs and their effectiveness as environmental sensors for heavy metals, showcasing strong capabilities in colorimetric detection. [ABSTRACT FROM AUTHOR]

This study reports the reduction of AgNO3 using green-synthesized carbon dots (CDs) derived from the leaf extract of Datura metel without the aid of any chemical-reducing agent. The CDs act as both reducing and stabilizing agent to synthesize CDs-functionalized silver nanoparticles (Ag/CDs) and are employed for surface-enhanced Raman spectroscopy (SERS)-based detection of thiram fungicide. The formation of Ag/CDs is confirmed with UV–Vis absorption spectroscopy and Raman spectroscopy. The synthesized Ag/CDs exhibit high stability and the fabricated SERS substrate exhibited a detection range of 10–3 to 10–8 M with a corresponding correlation coefficient of 0.98. The obtained minimum detection limit of thiram is 10–8 M with an enhancement factor of 1.3 × 105 which is much lower than the maximum allowed residual limit of 7 ppm. This study emphasizes the green route to synthesize CDs-functionalized stable AgNPs for the SERS-based detection of thiram fungicide and explained the sensing mechanism. [ABSTRACT FROM AUTHOR]

Over the past few decades, the green synthesis of nanoparticles has gained importance for their therapeutic efficacy and eco-friendly nature. Integrating green chemistry principles into multidisciplinary nanoscience research has paved the way for developing environmentally benign and sustainable methods for synthesizing gold and silver nanoparticles. In the present study, the flowers obtained from Clerodendrum infortunatum (L.), belonging to the family Verbenaceae, have been used for biosynthesizing silver nanoparticles (AgNPs) to evaluate the anthelmintic potential. UV–Vis spectroscopy, XRD, FTIR, SEM and TEM analyses were performed to ascertain the formation of AgNPs. Clerodendrum-derived AgNP (CLE-AgNP) has significantly affected the normal physiological functions of the poultry parasite Raillietina spp., a menace to the livestock industry. Our study manifests that CLE-AgNPs cause considerable distortion of the surface tegument of this cestode parasite leading to changes in the host-parasite interface. The histochemical localization studies of the tegument-associated enzymes viz. AcPase, AlkPase, ATPase and 5'-Nu, exposed to the drug, showed a substantial activity decline, thus establishing the anthelmintic potential of the CLE-AgNPs. [ABSTRACT FROM AUTHOR]

Green synthesis of bioactive nanoparticles (NPs) is getting more attractive in various fields of science including the food industry. This study investigates the green synthesizing and characterization of gold NPs (AuNPs) and silver NPs (AgNPs) produced using Mentha spicata L. (M. spicata) essential oil as well as their antibacterial, antioxidant, and in vitro cytotoxic effects. The essential oil was mixed with both Chloroauric acid (HAuCl4) and aqueous silver nitrate (AgNO3) solutions separately and incubated at room temperature for 24 h. The chemical composition of the essential oil was identified by gas chromatography coupled with a mass spectrometer detector (GC–MS). Au and Ag nanoparticles were characterized using UV–Vis spectroscopy, transmission electron microscopy, scanning electron microscopy, dynamic light scattering (DLS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The cytotoxicity of both types of nanoparticles was evaluated using MTT assay on cancerous HEPG-2cell line by exposing them to various concentrations of both NPs for 24 h. The antimicrobial effect was evaluated by the well-diffusion technique. The antioxidant effect was determined by DPPH and ABTS tests. According to the results of GC–MS analysis, 18 components were identified, including carvone (78.76%) and limonene (11.50%). UV–visible spectroscopy showed a strong absorption peak of 563 nm and 485 nm, indicating the formation of Au NPs and Ag NPs, respectively. TEM and DLS demonstrated that AuNPs and AgNPs were predominantly spherical shaped with average sizes of 19.61 nm and 24 nm, respectively. FTIR analysis showed that biologically active compounds such as monoterpenes could assist in the formation and stabilization of both types of NPs. Additionally, XRD provided more accurate results, revealing a nano-metal structure. Silver nanoparticles exhibited better antimicrobial activity against the bacteria than AuNPs. Zones of inhibition ranging 9.0–16.0 mm were recorded for the AgNPs, while zones of 8.0–10.33 mm were observed AuNPs. In the ABTS assay, the AuNPs and AgNPs showed a dose-dependent activity and synthesized nanoparticles exhibited higher antioxidant activity than MSEO in both assays. Mentha spicata essential oil can be successfully used for the green production of Au NPs and Ag NPs. Both green synthesized NPs show antibacterial, antioxidant, and in vitro cytotoxic activity. [ABSTRACT FROM AUTHOR]

Green synthesized nanoparticles (GSNPs) display fascinating properties compared to physical and chemical synthesized ones. GSNPs are currently used in numerous applications such as food packaging, surface coating agents, environmental remediation, antimicrobial, and medicine. In the present study, the aqueous leaf extract of Perilla frutescens L. having suitable capping, reducing, and stabilizing compounds was used for green synthesis of silver nanoparticles (Pf-AgNPs). The bioreductant capacity of aqueous leaf extract of P. frutescens for Pf-AgNPs was determined by different confirmatory techniques including UV–Visible spectroscopy, XRD, FESEM, EDX, zeta potential, DLS, SERS, and FTIR analysis. The results exhibited that Pf-AgNPs had optimal size (< 61 nm), shape (spherical), and stability (− 18.1 mV). The antioxidant activity of Pf-AgNPs with both DPPH and FRAP assays was significantly higher compared to P. frutescens extract. Furthermore, Pf-AgNPs had high antimicrobial activity against Escherichia coli and Staphylococcus aureus (MIC = 0.78 mg/mL), and Candida albicans (MIC = 8 mg/mL) while the plant extract showed low antimicrobial activity against both bacterial strains and the fungus tested. Pf-AgNPs and P. frutescens extract also exhibited moderate toxicity on MCF-7 cancer cells with IC50 values of 346.2 and 467.4 µg/mL, respectively. The results provide insights into using the biosynthesized Pf-AgNPs as an eco-friendly material for a wide range of biomedical applications. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been widely studied due to their interesting physicochemical properties and remarkable antibacterial properties. Chemical synthesis methods, including green chemistry, have achieved 0D nanostructures. However, ecological methods have little studied self-assembling Ag nanostructures, such as flowers or dendrites. In this work, Ag dendrites and Ag flower-like morphologies have been successfully synthesized using a one-step green method employing Arctostaphylos pungens Kunth fruit extract at room temperature. The antibacterial properties of both nanostructures were evaluated against Gram-positive Escherichia coli and Gram-negative Staphylococcus aureus bacteria. Scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), and infrared spectroscopy (IR) characterized the synthesized products. The morphological changes of the nanostructures come from the variation in the concentration of the precursor salt, silver nitrate (AgNO3). A growth mechanism is proposed that includes the formation of nanospheres and their subsequent transformation into Ag dendrites. Both nanostructures show good antibacterial activity against the tested microorganisms. The Ag dendritic nanostructures presented inhibition zones of 11 mm and 10.7 mm against Escherichia coli and Staphylococcus aureus bacteria. However, the flower-like structure was slightly less effective, presenting 11 and 9.5 mm inhibition zones against the same microorganisms, respectively. [ABSTRACT FROM AUTHOR]

In the present study, the silver nanoparticles (AgNPs) were synthesized from the bulbs of Allium sativum, characterized by UV–visible spectroscopy, FT-IR, SEM, HR-TEM, EDAX analysis and investigated its action on the inhibition of starch digestion. The results proved that the biosynthesized nanoparticles were uniformly dispersed, spherical shaped with the size ranging from 10 to 30 nm. The phytochemical and FT-IR analysis showed the presence of phenols, terpenoids, and amino acids in the synthesized AgNPs. The cytotoxicity analysis revealed that the synthesized AgNPs were non-toxic to the normal cells. The synthesized AgNPs exhibited significant free radical scavenging activity. The in vitro antidiabetic activity showed that the synthesized AgNPs increased glucose utilization, decreased hepatic glucose production, inhibited the activity of starch digestive enzymes such as α-amylase and α-glucosidase, and were not involved in the stimulation of pancreatic cells for the secretion of insulin. The in silico antidiabetic activity analysis (molecular docking) also revealed that the silver atoms of the AgNPs interacted with the amino acid residues of α-amylase, α-glucosidase, and insulin. The present study proved that the AgNPs synthesized from A. sativum have prominent antidiabetic activity in terms of reducing the hyperglycemia through the increased glucose utilization, decreased hepatic glucose production, and the inhibition of α-amylase and α-glucosidase enzymes. So it can be used as a promising nanomedicine for the treatment of diabetes. [ABSTRACT FROM AUTHOR]

Nanofluids are a class of fluids prepared by dispersing nanoparticles in conventional base fluids. Owing to their excellent thermo-physical properties, nanofluids find potential applications in manufacturing industries. They are introduced to overcome the limitation with using traditional base fluids like water having low thermal conductivity (~ 0.612 W/mK at room temperature). The thermal conductivity of a base fluid is considerably increased by adding a modest number of nanoparticles to it. In the present work, we have prepared silver nanoparticles and nanorods using the simple chemical reduction method. UV–Visible spectroscopy and field emission scanning electron microscopy were used to investigate the optical characteristics and morphology of the produced nanomaterials. Furthermore, the effect of volume loadings of produced nanomaterials (0, 2%, 4%, 6%), as well as temperature on the thermal conductivity of the base fluids was investigated. The results are compared to different silver nanoparticles (AgNPs) loadings in the base fluid. Both silver nanoparticles and nanorods have optimal heat conductivity at 2 vol%. It is interesting to note that fluids with silver nanorods (AgNRs) portrayed better results compared to nanoparticles and the maximum enhancement observed of 78.4% for AgNRs-based nanofluids at temperature 323 K, which is very high when compared to most of the previously reported values. [ABSTRACT FROM AUTHOR]

The science of nanotechnology is expanding daily and has the potential to benefit people. Moringa oleifera is an abundant source of phenolic compounds, which are bioactive substances. It is recognised as a necessary plant because of its medicinal potential and a wide variety of health benefits. The aim of the current study is to examine the antioxidant, antibacterial, and cytotoxicity effects of five nanoparticles (La2O3, CuO, Fe2O3, Ag, and ZnO) made using bioactive chemicals in the aqueous extract of Moringa oleifera leaves on four human cell lines (T47D, HepG2, A549, and Wi38). The UV–visible spectroscopy analysis with a surface plasmon peak in the 300–490 nm range and the value of the zeta potential of the various biosynthesized nanoparticles ranged from + 31 to + 37 mV, indicated the repulsion between the particles and the stability of the formulation nanoparticles confirmed the formation of all nanoparticles. Additionally, the DPPH method was used to assess the antioxidant activity of five distinct metal nanoparticles. The results show that this method works in parallel and is dependent on both the concentration of NPs and the incubation time. The anticancer effect of synthesized nanoparticles against four different cell lines has been tested. The cytotoxicity assay showed a dose-dependent and time-dependent effect of nanoparticles. The obtained results conclude that acceptable potency against T47D and A549 cell lines with IC50 ranged from 38 to 210 μg/mL and 26 to 115 μg/mL, respectively. However, HepG2 and Wi38 cell lines showed relatively higher resistance against all tested nanoparticles when compared with Doxorubicin. Moreover, the antibacterial results revealed that silver nanoparticles exhibited the highest antibacterial activity against both Enterococcus faecalis and Staphylococcus aureus. Nanoparticles' high therapeutic activity at low concentrations opens up new avenues for the development of novel therapeutic approaches against human pathogens. [ABSTRACT FROM AUTHOR]

In this study we aim to investigate the computational docking approach of biofabricated silver nanoparticles against P. aeruginosa virulent exoenzymes, such as ExoS and ExoY. Therefore, the synthesis and characterization of biofabricated silver nanoparticles using Piper betle leaves (Pb-AgNPs) were carried out. The surface topology and functional group attachment on the surface of Pb-AgNPs were analyzed using UV–visible spectroscopy, Scanning Electron Microscopy, Fourier Transformed Infrared Spectroscopy (FTIR), and X-Ray Diffraction. The FTIR analysis revealed that the synthesized silver nanoparticles were capped with P. betle phytochemicals importantly Eugenol and Hydroxychavicol. These are the major bioactive compounds present in P. betle leaves; therefore, computational docking of Eugenol-conjugated AgNPs (PbEu-AgNPs) and Hydroxychavicol-conjugated AgNPs (PbHy-AgNPs) against ExoS and ExoY was performed. The active residues of PbEu-AgNPs and PbHy-AgNPs interacted with the active site of ExoS and ExoY exoenzymes. Biofabricated AgNP-mediated inhibition of these virulent exoenzymes blocked the adverse effect of P. aeruginosa on the host cell. The computational analysis provides new approach into the design of biofabricated AgNPs as promising anti-infective nanomedicine agents. [ABSTRACT FROM AUTHOR]

Vancomycin hydrochloride (VANH) is a glycopeptide antibiotic commonly employed in the prophylaxis and therapy of various gram-positive bacterial life-threatening infections. Due to the narrow therapeutic window of VANH, its serum levels should be well-monitored to avoid its toxicity and to optimize its therapy. Herein, an innovative silver-nanoparticles enhanced fluorescence technique was designed for VANH rapid analysis in its pharmaceutical formulation and biological fluids. This technique is based on reinforcement of VANH fluorescence intensity with silver-nanoparticles that were synthesized by a redox reaction between VANH and silver nitrate in NaOH alkaline medium using polyvinylpyrrolidone as a stabilizer. The produced silver-nanoparticles were characterized by using UV–visible spectroscopy where they have an intense absorption maximum at 415 nm and transmission electron microscope (TEM) micrograph where they are spherical in shape with smooth surface morphology and size of 10.74 ± 2.44 nm. The fluorescence intensity was measured at 394 nm after excitation at 259 nm. Under optimum conditions, a good linear relationship was accomplished between the VANH concentration and the fluorescence intensity in a range of (1–36) ng/mL with a limit of detection of 0.29 ng/mL. Greenness assessment was performed using two assessment tools namely; eco-scale scoring and green analytical procedure index revealing excellent greenness of the proposed technique. The proposed technique was validated according to the International Conference on Harmonisation (ICH) recommendations and statistically compared with the reported HPLC method revealing no significant difference concerning accuracy and precision at p = 0.05. The proposed technique depended primarily on water as a cheap and eco-friendly solvent. [ABSTRACT FROM AUTHOR]

This work used Sedum praealtum leaf extract to synthesize silver nanoparticles (AgNPs) in a single step. The cytotoxicity of AgNPs was studied with the yeast Saccharomyces cerevisiae W303-1. In addition, the antioxidant activity of the DPPH radical was studied both in the extract of S. praealtum and in the AgNPs. UV–Vis spectroscopy determined the presence of AgNPs by the location of the surface plasmon resonance (SPR) band at 434 nm. TEM and XRD analyzes show AgNPs with fcc structure and hemispherical morphology. Also, AgNPs range in size from 5 to 25 nm and have an average size of 14 nm. 1H NMR, FTIR, and UV–Vis spectroscopy techniques agreed that glycosidic compounds were the main phytochemical components responsible for the reduction and stabilization of AgNPs. In addition, AgNPs presented a maximum of 12% toxicity in yeast attributed to the generation of ROS. Consequently, there was low bioactivity because glycoside compounds cover the biosynthesized AgNPs from S. praealtum. These findings allow applications of AgNPs involving contact with mammals and higher organisms. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were in situ generated on the surface of cellulose matrix using leaf extract of cissampelos pareira (LCP) by environmentally benign green synthesis. The morphological and structural properties of synthesized cellulose silver nanocomposites (Cel/LCP/Ag-NCs) were characterized by different spectral studies such as UV–visible spectroscopy, SEM, TEM, FT-IR, AFM, DRS, PL, Lifetime, XPS and XRD. Silver nanoparticles were obtained in the cellulose matrix with an average size of 34.26 nm and with antioxidant activity which has been evaluated by ABTS (70.34% at 100 µg/mL) and DPPH (81.65% at 100 µg/mL) methods. The antimicrobial properties of cellulose, Cel/LCP, Cel/LCP (10 mM, 30 mM and 50 mM AgNO3), tested on 13 microorganisms were determined using disk diffusion method. The most effective nanocomposites (Cel/LCP/10, 30 and 50 mM AgNO3), Cel/LCP/50 mM AgNO3 afforded the best antimicrobial properties because increasing the concentration of AgNO3 solution, the zone of inhibition also increased. The prepared cellulose silver nanocomposites synthesized by leaf extract of cissampelos pareira shows the potential to be applied in the future development of therapeutics and biomedical applications. [ABSTRACT FROM AUTHOR]

The fluorescent silver nanoparticles were synthesized using trisodium citrate as a reducing and stabilizing agent in a microwave-assisted reduction process. The influence of synthesizing parameters such as reaction duration, temperature, and trisodium citrate concentration (100, 200, and 400 ppm) were examined on the characteristics and fluorescent properties of synthesized silver nanoparticles (AgNPs). The formation of AgNPs was studied by UV–Vis absorption spectroscopy, X-ray diffraction, ATR-FTIR spectra, and scanning electron microscopy. The low concentration compared to the high concentration of trisodium citrate resulted in a prolonged reduction process, and also the high concentration resulted in the formation of smaller AgNPs (44 nm). The fluorescence emission spectra of the synthesized colloidal AgNPs demonstrated a quite explicit emission peak centered around 335 nm. However, the higher reaction temperature (above 100 °C) resulted in a sharp and narrow emission peak. The synthesized silver nanoparticles exhibited a suitable fluorescent property, which was reliant on the size of synthesized AgNPs. [ABSTRACT FROM AUTHOR]

In this study, platinum nanoparticles (Pt NPs) were synthesized by a green method using an aqueous extract of Eucalyptus camaldulensis with assistance of microwave irradiation (850 W) and their physicochemical characteristics were studied by UV–visible spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. Antioxidant activities, hemocompatibility, and cytotoxic effects of the prepared Pt NPs were then evaluated. The attained results showed that the newly formed Pt NPs possess a size range between 7.4 and 11.2 nm. These spherical-shaped NPs were slightly aggregated and held various functional groups on their surface. The antioxidant activity of Pt nanostructures was comparable to that of butylated hydroxyl anisole at concentrations higher than 320 µg/mL. At the same concentration of 640 μg/mL, the scavenging activities were 3.36 ± 0.9% (hexachloroplatinic acid) and 52.13 ± 0.43% (Pt NPs). The results of hemolytic assay revealed satisfactory hemocompatibility of the Pt NPs even at the concentration as high as 4 mg/mL (hemolysis percent equal to 3.5 ± 1.3%). The cytotoxicity studies revealed that MCF-7, A549, and 3T3 cell lines treated with hexachloroplatinic acid and cisplatin for 24 h and 48 h showed a higher percentage of cell death compared with the Pt NPs. After 24 h, for A549, 3T3, and MCF-7 cells exposed to Pt NPs, the cell viability was measured to be 80 ± 3.2%, 96 ± 1%, and 89 ± 2.6%, respectively, at concentration of 640 µg/mL. Further investigations are required to elucidate the mechanisms behind the biological activities of as-synthesized Pt NPs. [ABSTRACT FROM AUTHOR]

In this study, we aimed at the green synthesis of silver nanoparticles (AgNPs) using Lavandula angustifolia extract and the investigation of the anti-proliferative and apoptotic inducing effects of these nanoparticles in the U87MG glioblastoma cancer cell line. Green synthesized silver nanoparticles were characterized by various analytical techniques such as UV–Visible Spectrophotometer (UV–Vis), scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX). UV–Vis spectroscopy displayed a specific silver plasmon peak at 430 nm. U87MG cells were treated at increased concentrations with Lavandula angustifolia-AgNPs (La-AgNPs) (0–20 µg/mL) for 72 h and the anti-proliferative effects of green synthesized silver nanoparticles on U87MG cells were evaluated by MTT assay. The La- AgNPs induced a statistically significant dose-dependent decrease in proliferation and increased cytotoxicity in U87MG cells. The IC50 value is 7.536 µg/mL. Furthermore, the expression of apoptosis proteins caspase-3, caspase-8 and caspase-9 was analyzed using ELISA and caspase-3 and p53 using western blotting. The results suggest that La-AgNPs induce cell death in U87MG cells through the p53 mediated intrinsic apoptotic pathway. Together, the present findings suggest that La-AgNPs could be considered as a potential option for the treatment of glioblastoma. [ABSTRACT FROM AUTHOR]

Many studies have concentrated on exploring behaviors of nickel silver oxide nanoparticles using various routes of fabrication. Thermal treatment technique has never been utilized to fabricate nickel oxide silver oxide nanoparticles. In this research, binary (NiO)0.4 (Ag2O)0.6 nanoparticles were synthesized using the thermal treatment method due to its attractive advantages such as low cost, eco-friendly, and purity of nanoparticles. The structural, morphological, and optical behaviors of these nanoparticles were investigated at different calcined temperatures. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–Vis), and photoluminescence (PL) were the techniques used to characterize the synthesized nanoparticles. XRD was conducted at different calcined temperatures. The crystallite size was increased from 25.4 nm to 37.0 nm as the calcined temperature increased from 500 °C to 800 °C. Also, TEM results verified that the mean particle size was enlarged as the calcined temperatures increased. Two band gaps were found for each temperature, which were decreased from (3.05, 2.45) to (2.70, 1.95) eV as the temperature varied from 500 to 800 °C, respectively. Broadbands were observed by PL spectra, and the intensity of two emission peaks was also increased at higher temperatures. The results approved the successful formation of binary (NiO)0.4 (Ag2O)0.6 nanoparticles by a novel facile synthesis route. These nanoparticles are likely to have various applications, especially optical applications due to the formation of two band gaps. [ABSTRACT FROM AUTHOR]

In this study, we aimed at the green synthesis of silver nanoparticles (AgNPs) using Lavandula angustifolia extract and the investigation of the anti-proliferative and apoptotic inducing effects of these nanoparticles in the U87MG glioblastoma cancer cell line. Green synthesized silver nanoparticles were characterized by various analytical techniques such as UV–Visible Spectrophotometer (UV–Vis), scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX). UV–Vis spectroscopy displayed a specific silver plasmon peak at 430 nm. U87MG cells were treated at increased concentrations with Lavandula angustifolia-AgNPs (La-AgNPs) (0–20 µg/mL) for 72 h and the anti-proliferative effects of green synthesized silver nanoparticles on U87MG cells were evaluated by MTT assay. The La- AgNPs induced a statistically significant dose-dependent decrease in proliferation and increased cytotoxicity in U87MG cells. The IC50 value is 7.536 µg/mL. Furthermore, the expression of apoptosis proteins caspase-3, caspase-8 and caspase-9 was analyzed using ELISA and caspase-3 and p53 using western blotting. The results suggest that La-AgNPs induce cell death in U87MG cells through the p53 mediated intrinsic apoptotic pathway. Together, the present findings suggest that La-AgNPs could be considered as a potential option for the treatment of glioblastoma. [ABSTRACT FROM AUTHOR]

The present work describes the biofabrication of highly stable, water-dispersible mycogenic silver/silver (I) oxide nanoparticles (Ag/Ag2O NPs) alongside its potential applications in non-enzymatic electrochemical glucose sensing and catalytic degradation of methylene blue (MB) dye in presence of reducing agent NaBH4. These Ag/Ag2O NPs were fabricated from silver oxide micro powder using endophytic fungus Fusarium oxysporum based environmentally friendly, bio-inspired, top-down approach which is highly reproducible, reliable, and cheap. Bacterial and plant-mediated bottom-up approaches have been previously reported for the production of Ag/Ag2O NPs. Bacterial methods are not economical as they require expensive sophisticated instruments for separation and purification. Similarly, plant-based means of synthesis are not reliable and reproducible due to geographical and seasonal variability's. UV–Visible spectroscopy, TEM, SAED, FTIR, XRD, TGA, and DSC were used for the characterization and investigation of thermal properties of mycogenic nanoparticles and their antimicrobial activity was evaluated by filter- paper bioassay technique. [ABSTRACT FROM AUTHOR]

Delonix regia has bioactive phytochemicals present in leaves, seeds, roots, and flowers. Considering that these compounds are common in extracts used for silver nanoparticles (AgNPs) biosynthesis, this study investigated the potential of D. regia seeds aqueous extract (DRE) in different concentrations to produce AgNPs (DRE-AgNPs). DRE composition was investigated by qualitative assays, and physico-chemical/structural characterization of AgNPs was performed by UV–Visible spectroscopy, dynamic light scattering (DLS), Zeta potential, and atomic force microscopy (AFM). Antibacterial effect of DRE-AgNPs was evaluated against Escherichia coli and Staphylococcus aureus. DRE presented mainly tannins and saponins. Additionally, the absorbance of each DRE-AgNPs was positively correlated to DRE concentration. At higher DRE concentrations, AgNPs were larger, regarding Z average; tended to monodispersity; and presented more negative Zeta potentials. Hydrodynamic diameters of DRE-AgNPs were measured by number distribution and only AgNPs synthesized with DRE 2 mg ml−1 (DRE-AgNPs 2) presented a single population of particles. Thus, DRE-AgNP 2 was analyzed by AFM and exhibited a spherical shape and an average height of 18.39 ± 1.59 nm. Most of DRE-AgNPs presented antibacterial effects against E. coli and S. aureus at 128 or 256 µmol l−1. In conclusion, different DRE concentrations modulated physico-chemical characteristics of AgNPs with antibacterial activity. [ABSTRACT FROM AUTHOR]

The present work describes the biofabrication of highly stable, water-dispersible mycogenic silver/silver (I) oxide nanoparticles (Ag/Ag2O NPs) alongside its potential applications in non-enzymatic electrochemical glucose sensing and catalytic degradation of methylene blue (MB) dye in presence of reducing agent NaBH4. These Ag/Ag2O NPs were fabricated from silver oxide micro powder using endophytic fungus Fusarium oxysporum based environmentally friendly, bio-inspired, top-down approach which is highly reproducible, reliable, and cheap. Bacterial and plant-mediated bottom-up approaches have been previously reported for the production of Ag/Ag2O NPs. Bacterial methods are not economical as they require expensive sophisticated instruments for separation and purification. Similarly, plant-based means of synthesis are not reliable and reproducible due to geographical and seasonal variability's. UV–Visible spectroscopy, TEM, SAED, FTIR, XRD, TGA, and DSC were used for the characterization and investigation of thermal properties of mycogenic nanoparticles and their antimicrobial activity was evaluated by filter- paper bioassay technique. [ABSTRACT FROM AUTHOR]

Due to the broad-spectrum of antibiotic resistance, herein we investigated the possibility of using imipenem-conjugated silver nanoparticles (IMP-AgNPs) against multidrug-resistant isolates of Pseudomonas aeruginosa. For this purpose, 200 clinical isolates were tested against different antibiotics to determine the antimicrobial susceptibility. To identify blaVIM and blaIMP resistance genes, PCR was used. The synthesized AgNPs and conjugants were characterized using UV-vis spectroscopy, XRD, SEM, TEM, DLS, and FTIR. The stability, drug release kinetics, cytotoxicity, hemolytic and apoptotic effects of NPs were also investigated. MIC of the imipenem, AgNPs, and conjugants were evaluated versus P. aeruginosa isolates. Finally, the effects of the IMP-AgNPs to heal burn wounds in rats was evaluated. According to the results, about 68% of isolates showed resistance to imipenem (MIC ≥ 64 μg/ml to ≥ 512 μg/ml). Analytical results verified the synthesis of AgNPs and IMP-AgNPs. A Dose-dependent decrease happened in terms of the MIC values of IMP-AgNPs were also affected by the existence of resistant genes. Low cytotoxic was observed regarding AgNPs which lead to apoptosis. The histopathological results showed a considerable epithelization in treated groups with IMP-AgNPs. Accordingly, IMP-AgNPs can be considered as a powerful antibacterial agent to treat the infections caused by multidrug-resistant P. aeruginosa. [ABSTRACT FROM AUTHOR]

Bioengineered green approaches of metal nanomaterials plays an extensive role against current environmental affairs and clinical pathogens. In the current exploration, biomolecule loaded silver nanoparticles (AgNPs) were engineered by microwave irradiation mode using the leaf extracts of Ludwigia octovalvis and characterized by Ultraviolet–visible spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. FTIR revealed feasible biomolecules available in capping and bioreduction of AgNPs. XRD result clearly pinpoints the crystallinity of the synthesized AgNPs. FESEM analysis taped that AgNPs were found to be polyhedrons in nature with average size 28–50 nm. The antimicrobial properties of AgNPs was investigated against different bacterial pathogens (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris and Staphylococcus epidermidis). A potential anti-biofilm activity of phytocompounds loaded AgNPs against P. aeruginosa and S. epidermidis were recorded. As well, the enhanced decolouration action of AgNPs were detected against deadly pollutant dyes Alizarin red, Congo red, Methylene blue and Rhodamine b. The outcome undoubtedly indicated that the AgNPs may be considered as an successful nano based therapeutic drug for various diseases caused by pathogens and vigorous catalytic agent against toxic dyes. [ABSTRACT FROM AUTHOR]

The plant extracts were applied for synthesis of Ag-nanoparticles and expected such biological processes benefit from advantages like eco-friendly, cost-effective, and safe for human use. Accordingly, polyphenol compounds and antioxidant properties of this understudy plant extract was initially qualified and quantified by GC-Mass and subsequently its ability for silver nanoparticle (AgNP) biosynthesis was examined. Consequently, under study (ethanol) extract was exposed to various content of AgNO3 solution over 0, 2.5, 5, 7.5, 10 and 15 mM for 24, 48, 72 and 96 h to search best operational conditions for AgNPs production, while sampling were done every 24 h monitoring initial absorption with UV–Vis spectroscopy. The peak with center at 460 nm emerged from surface plasmon resonance of AgNPs which is good indication of successful formation of AgNPs. The nanoparticles were characterized by DLS, SEM, TEM, XRD, and FTIR. Which reveal its spherical, shape and average diameter of 32 nm. Antioxidant activity tests showed that the half-maximal inhibitory concentration (IC50) in the C. tuberculata extract was 4.722 mg/ml. Antimicrobial activity of the AgNPs was tested by measurement of inhibition zone around discs modified with AgNPs in cultures of S. aureus, B. cereus, P. aeruginosa and E. coli. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles using plant extracts is popular because of its ease, simplicity and wide applications. Here we report the synthesis of silver nanoparticles (AgNPs) by Caesalpinia pulcherrima leaf extract. Optimization of various parameters like boiling time for plant extract preparation, concentration of plant extract and silver nitrate, pH and incubation time of reaction mixture were standardized. AgNPs were synthesized using standardized and optimized parameters. The characterization of synthesized AgNPs was done by various spectroscopic methods. UV–Vis spectroscopy showed characteristic peak at 410 nm, FTIR analysis indicated the presence of alcohols, carboxylic acids, esters and ethers. XRD confirmed the crystalline nature of AgNPs while TEM revealed the particles to be spherical in shape with an average size of 9 nm. The synthesized AgNPs showed good antimicrobial activity especially more against Gram negative bacteria. The cytotoxicity effect was dose dependent and genotoxic study revealed non toxic nature at lower concentration. [ABSTRACT FROM AUTHOR]

This study aims to examine the biosynthesis and characterization of silver nanoparticles using Lavatera cretica (LCAgNPs) leaf extract mixed with silver nitrate and improving their glucose bigotry. The biosynthesis was first confirmed by the color change from colorless (metal salt solution) to brown (nanoparticle colloidal dispersion). The occurrence of the nanoparticles was further ascertained by several physicochemical studies including UV–Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) tomography, Fourier transform-infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The UV–Vis spectroscopy of LCAgNPs indicated the surface plasmon resonance signature of Ag NPs at around 440 nm. The TEM analysis revealed a well-dispersed sphere that varied in size from 5 to 24 nm. The EDX results established that Ag was the major element and others such as C, O and Cl were also present, which specified that the biomolecules coincided the AgNPs. The FT-IR spectroscopic study exhibited that the functional groups such as O–H, C–O, N–H, C–H and C=O were accountable for the synthesis of AgNPs. The XRD pattern represented the crystalline nature of metallic Ag. In this results, it could be clinched that the silver nitrate was reduced to silver nanoparticles of small size and high stability, which were devoid of impurities. Hence, this study has proved that L. cretica leaf is a good source for the synthesis of AgNPs and their improved glucose bigotry. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) using a number of biological agents such as extracts from various parts of the plants have garnered remarkable attention recently. The aim of the study was a green synthesis of AgNPs using stems and flowers of Felty germander (Teucrium polium L.). After collection and preparation of the aqueous extract, production of AgNPs was performed. In the study, effect of parameters including AgNO3 concentration (1, 5, 10, 15, 20, 25, and 50 mM), aqueous extract (100 µl, 150 µl, 300 µl, 600 µl and 900 µl), pH value (between 0 and 14), incubation time (5, 10, 15, 20, 25, and 30 min), and temperature (30 °C, 60 °C, and 90 °C) were investigated in the synthesis of AgNPs. The sufficient production was achieved at the room temperature (30 °C), duration of 15 min, pH of 6 and concentration of 7.5 mM of AgNO3. Finally, the antifungal activity of these nanoparticles was also studied on Fusarium oxysporum by colony formation assay. The production of AgNPs was identified by an absorption peak at approximately 450 nm using UV–Visible spectroscopy. According to XRD, DSL, FESEM, and PSA results and analysis of SEM, nanoparticles have almost spherical shape and size of 10 to 100 nm. The SEM images also revealed that the prepared AgNPs are particles with no agglomeration. Furthermore, the TEM images exhibited that the AgNPs were well dispersed and there was no evident aggregation. Absorption peaks at 3391.55, 2917.00, 2848.83, 1640.15, 1384.65, 1243.37, 1069.07 and 614.54 cm−1 were observed for the AgNPs using FTIR analysis. On the other hand, the antifungal analysis revealed that these AgNPs have antifungal activity. For the first time, the biosynthesis of AgNPs was successfully performed using the aqueous extract of Felty germander which is a rapid, inexpensive and safe approach. Furthermore, the resulting AgNPs has antifungal activity. [ABSTRACT FROM AUTHOR]

The rapid formation of spherical and hexagonal silver nanostructures (Ag colloid particles of different shapes) through microwave irradiation was investigated. Silver nanoparticles were successfully fabricated by reduction of Ag+ in a water medium and using polyvinylpyrrolidone as stabilizing and ethanol as reducing agents, while varying microwave power. The preliminary synthesis of silver nanoparticles was observed through the color change of the solution, from colorless transparent to brown. Morphological observations using transmission electronic microscopy indicated the formation of spherical-shaped particles at the nanoscale regime (2–100 nm) with high crystalline nature. Elementary analysis confirms the purity of AgNPs and surface plasmon resonance reactivity of their specific surface. UV–Visible spectroscopy revealed the existence of two kinds of AgNPs: metallic and ionic species exhibiting an interesting optical property in the ultraviolet range. The auto-correlation function measured by dynamic light scattering displayed a monodispersed character of AgNPs with an average particle size around 111 nm. Additionally, the antibacterial activity measured by Kirby–Bauer method indicated that silver nanoparticles exhibit high antibacterial activity against Gram+ bacteria such as Staphylococcus aureus M55A and Gram− such as Escherichia coli BCSE, Klebsiella pneumoniae Kpc+ , Salmonella spp. [ABSTRACT FROM AUTHOR]

In present study, silver nanoparticles (AgNPs) were synthesized using Eucalyptus tereticornis leaves extract as bioreducing agent. Prepared AgNPs were characterized and confirmed using various analytical tools such as UV–Vis spectroscopy, XRD, SEM with EDS and TEM. Crystallographic studies were carried by XRD analysis. Size, morphology was studied by SEM, TEM and elemental composition confirmed by EDS respectively. AgNPs showed significant antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacterial strains. AgNPs also exhibited promising 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity with IC50 59.0 μg/mL. Further, cytotoxic activity performed on Michigan Cancer Foundation-7 (MCF-7) cell line proved that the prepared AgNPs have potential anticancer activity having 63.257 μg/ml 50% inhibition concentration. [ABSTRACT FROM AUTHOR]

This study reports on the bioactive potential of silver nanoparticle synthesized from seaweed, Cladophora fascicularis aqueous extract. C. fascicularis assisted silver nanoparticles (Cf-AgNPs) was characterized by UV–visible spectroscopy, XRD, FT-IR, FESEM, TEM, and EDX analysis. The Cf-AgNPs exhibited a maximum absorption peak at 427 nm. The carboxyl (–C=O) and amine (N–H) groups of C. fascicularis extract is answerable for the synthesis of Cf-AgNPs. The microscopic analysis confirmed that the synthesized Cf-AgNPs are spherical in shape with an average size of 45 nm. The Cf-AgNPs exhibited a dose depended antibacterial activity against Aeromonas hydrophila. Noteworthy bacterial inhibition (19 mm) was observed at 150 µg/ml, whereas, the lowest activity (10 mm) was recorded at 25 µg/ml. Similarly, Cf-AgNPs significantly (P < 0.05) enhanced the protein leakage in A. hydrophila by increasing the membrane permeability. The considerable amount of ROS activity was noticed in the test bacterium A. hydrophila when treated with 150 µg/ml of Cf-AgNPs. The toxicity investigation results revealed that the synthesized Cf-AgNPs were not acutely toxic to Artemia nauplii even at a higher concentration (150 μg/ml). These results underline that Cf-AgNPs effectively inhibited the growth of A. hydrophila and showed the non-toxic effect with outstanding biocompatibility. [ABSTRACT FROM AUTHOR]

Nitrobenzene (NB) is a highly toxic and hazardous compound that needs to be detected at the low level. The current work describes an eco-friendly synthesis of silver nanoparticles (SNPs) using a Eucalyptus extract as reducing and stabilizing agent and its use for electrochemical detection of NB. The synthesized SNPs were characterized by following techniques UV–visible spectroscopy, powder X-ray diffraction, FESEM, HRTEM and TEM, FTIR spectroscopy. Further electrochemical investigation of SNPs-modified glassy carbon electrode (SNPs/GCE) is carried out by cyclic voltammetric and differential pulse voltammetric techniques. The prepared NPs exhibit excellent electrochemical behaviour towards reduction of NB and show a linear response in the range 5–40 µM, sensitivity of 2.262 µA µM−1 cm−2 and limit of detection of 0.027 µM. SNPs/GCE shows good selectivity towards NB detection. Also, the system exhibits a considerable recovery towards NB detection in of water and waste samples. [ABSTRACT FROM AUTHOR]

Strategies to design novel antibacterial materials may rely on the combination of materials to achieve synergistic effects. The coupling of antibacterial peptides to nanoparticles, however, needs to be directed conveniently to avoid structural changes within the peptide and/or degradation of the nanoparticle. Here, we present the results of the attachment of a synthetic peptide (VIHGW-alkyne-G-NH2) containing the amino terminal copper and nickel (ATCUN) motif to silver nanoparticles. In order to direct the peptide-nanoparticle coupling, the peptide was functionalized with an alkyne, whereas the nanoparticles were functionalized with azide groups using thiol-polyethylene glycol-azide (HS-PEG-N3) chains, so that the acetylide and the azide can undergo a click reaction. The reaction was conducted at room temperature and the steps in the construction of the nanoparticle-PEG-ATCUN array were followed by a combination of UV-Vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy. Evidence of the attachment of the PEG molecules through the thiol termination indicates that the nanoparticle is functionalized with azide groups, although only partially. The click reaction with the synthetic peptide is evidenced by the loss of the N3-vibrational signal with infrared spectroscopy. Throughout the steps of the synthesis, the behavior of the nanoparticles was followed by UV-Vis spectroscopy, dynamic light scattering, and zeta potential measurements, observing that during the process there are no significant changes in the size of the nanoparticle and that the stability of the nanoparticles increases. Antibacterial tests, conducted using E. coli, showed that the activity of the Ag-PEG-ATCUN nanocomposites is higher than that of nanoparticles and ATCUN peptides separately. [ABSTRACT FROM AUTHOR]

The study reports a versatile, cost-efficient and ecofriendly protocol for the synthesis of biogenic silver nanoparticles (AgNPs) using the aqueous extracts of Quao Binh Chau, Stereospermum binhchauensis and Che Vang, Jasminum subtriplinerve and their application in antibacterial activity and catalysis. The AgNPs with varying morphology and physical properties have been optimized using the absorption measurements. The biogenic AgNPs have been characterized by Fourier transform infrared spectroscopy, UV–Vis spectroscopy, transmission electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and thermal behaviors. Stable crystalline AgNPs with average particle sizes of 20.0 nm and 8.0 nm were fabricated from aqueous extract of Quao Binh Chau and Che Vang, respectively. The phytochemicals from the extracts involved in reduction and stabilization of AgNPs are identified by FTIR spectra and thermal gravimetric analysis. Both the biosynthesized AgNPs show the potent antibacterial activity against four tested bacterial strains including Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Agrobacterium tumefaciens. High catalytic activity of the biogenic AgNPs in the degradation of toxic contaminants (4-nitrophenol and methyl orange) was observed. The antibacterial and catalytic activities are found to be size and phytochemical dependent. The antibacterial and catalytic activities of the biogenic nanoparticles would find applications in the biomedical and environmental fields. [ABSTRACT FROM AUTHOR]

Bio-inspired synthesis of iron oxide nanoparticles (FeONPs) has been carried out by eco-friendly, low cost, and facile method using an aqueous extract of Psidium guajava (PG) leaf as a potential reducing agent. The obtained FeONPs were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and energy-dispersive spectroscopy techniques. The surface plasmon resonance peak of FeONPs was found to be 310 nm. The FTIR spectra analysis indicates the presence of various functional groups in PG extract that are responsible for the biosynthesis of FeONPs. The XRD confirmed that FeONPs were indexed into the cubic spinel lattice structure. The SEM and TEM analysis confirmed the spherical morphology of FeONPs with particle size ranging from 1 to 6 nm. The superparamagnetic nature of the formulated FeONPs was determined using VSM. The FeONPs formulated inhibit the growth of six human pathogenic strains with strong activity chiefly against Escherichia coli and Staphylococcus aureus at low concentration when compared to other standard antibacterial drugs. It is noteworthy that the formulated FeONPs are efficient as an antibacterial agent. [ABSTRACT FROM AUTHOR]

Green synthesis of silver chloride nanoparticles (AgCl NPs) using commercial yeast extract has been carried out. The physico–chemical characterizations of AgCl NPs were carried out by UV–visible spectroscopy, XRD, FTIR, HR-SEM equipped with EDAX and TEM. In vitro efficacy of anti-mycobacterial properties of AgCl NPs were determined by agar well diffusion and Luciferase Reporter Phage (LRP) assay were used against Mycobacteriumsmegmatis (MC2155) and Mycobacteriumtuberculosis H37Rv respectively. This shows that the AgCl NPs have potential anti-myobacterial activity against Mycobacterium tuberculosis H37Rv. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles was synthesized by a simple and ecofriendly method using plant gums of Araucaria heterophylla, Azadirachta indica and Prosopis chilensis. The biosynthesised silver nanoparticles were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, Dynamic light scattering etc. Silver nanoparticles were tested for its antibacterial activity against Escherichia coli and Streptococcus sp. and anticancer activity against human breast cancer cell line (MCF 7) and also utilized for chromium removal. The particles were found to have antibacterial activity. [ABSTRACT FROM AUTHOR]

Biosynthesis of silver nanoparticles (CTNP's) by Clitoria ternatea flower in the aqueous extract was investigated. Synthesized nanoparticles were characterized by using UV–Visible spectroscopy, followed by DLS, Zeta potential, XRD, FTIR, SEM, and AFM. The biocompatibility nature of CTNP's was determined using erythrocytes model system. Cytotoxicity of CTNP's against MCF-7 and EAC cells were determined by using MTT and Trypan blue exclusion method and their IC50 was found to be 19.37 µg/mL and 24 µg/mL. Cytotoxic potential of CTNP's was further confirmed by clonogenic assay. Further in vivo studies using EAC mice model supports the anti-cancer potential of silver nanoparticles. Results found that the CTNP's effectively control the proliferation rate by inhibiting the ascites secretion and cellular density. Further quantification of VEGF, microvessel density counts and CAM assays show the anti-angiogenic potential of the CTNP's. The apoptotic inducing activity of CTNP's was confirmed by DNA fragmentation, fluorescent staining studies. More interestingly, EAC treated mice exhibit significant increase in lifespan (~ 2.25 fold) compared to control EAC mice. Interestingly CTNP's did not exhibit any secondary complications against normal mice. The present findings give an experimental proof that the CTNP's could serve as a promising candidate to overcome limitations of existing conventional cancer therapeutics. [ABSTRACT FROM AUTHOR]

Hydrogels were synthesized by grafting polyacrylamide onto dextran using N,N′-methylene-bis-acrylamide as a cross-linker. The hydrogels were converted into polyelectrolytes by alkaline hydrolysis, and samples having various concentrations of ionic groups were obtained. The swelling behavior of the hydrogels in distilled water at room temperature was studied. Silver nanoparticles were generated in situ into the hydrogel network by silver ion reduction with ultraviolet (UV) irradiation. A series of hydrogel–silver nanoparticle composites synthesized in cross-linked polymer matrix with various degree of hydrolysis were characterized by Fourier-transform infrared (FTIR) spectroscopy, UV–Vis spectroscopy, and scanning electron microscopy. The absorption bands indicated formation of polydisperse Ag nanoparticles of 20, 50, and 100 nm in size. The FTIR spectrum of the hydrogel confirmed a weak interaction between –NH2 groups of polymer chains and Ag nanoparticles that stabilizes the nanosystems. It was shown that such hydrogel matrices can be used as effective nanoreactors for synthesis of silver nanoparticles. The size of the nanoparticles depends on the degree of hydrolysis of the polyacrylamide as well as the irradiation time of the silver ions incorporated into the polymer matrix. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag NPs) were profitably synthesized from aqueous Amorphophallus paeoniifolius leaf extract at room temperature, using one step and eco-friend green synthesis. The leaf extract acts as reducing agent to the formation of Ag NPs from Ag+ ions. The development of Ag NPs through aqueous medium was confirmed by UV–Vis spectroscopy and the spectra show characteristic surface plasmon resonance of Ag NPs at 428 nm. Crystalline nature of the synthesized samples was affirmed by the XRD studies. The particles are predominantly grown via (111) plane of Ag crystal and the particles size was fall in the range of 20–26 nm calculated by Scheerrer's formula. Size and shape of Ag NPs were observed from the SEM and TEM characterization. The samples are almost having spherical shape particles and the size of the particles is lies between 20 and 30 nm. The energy peak at 3 keV in the EDS spectrum strongly supported that the synthesized sample is Ag. FTIR spectra exhibit the leaf extract containing various characteristic functional groups which should responsible for the reduction of Ag+ ions. Synthesized Ag NPs displayed as potential antibacterial candidate against both gram positive and gram negative bacterial. [ABSTRACT FROM AUTHOR]

In this study, rapid and cost-effective biosynthesis of silver nanoparticles (AgNPs) was synthesized by using Piper longum (P. longum) catkin extract. The bioreduction of AgNPs was initially confirmed by using UV–visible spectroscopy which exhibits characteristic absorption peak at 450 nm in 120 s when exposed to sunlight. The phytoconstituents responsible for the reduction of AgNO3 to Ag NPs were examined using Fourier transform infrared spectroscopy. The crystalline nature of Ag NPs was confirmed using the X-ray diffraction pattern. Morphological studies confirmed the synthesized Ag NPs were monodispersed and spherical in shape with the size ranging from 15 to 40 nm. The zeta potential analysis of the synthesized AgNPs exhibit negative value (− 24.3 mV), which indicates higher stability. Further, the proficiency of the synthesized AgNPs was evaluated against mastitis-causing bacteria. Hence, the Ag NPs showed the maximum zone of inhibition against Staphylococcus aureus (12.45 mm), Pseudomonas aeruginosa (12.34 mm), and Bacillus subtilis (9.75 mm). In addition, the catalytic efficiency of Ag NPs was investigated for the conversion of methyl orange to hydrazine derivatives, methylene blue to leuco methylene blue, and o-nitrophenol to o-aminophenol in 4, 5 and 3 min, respectively. Hence, this study explores the doctrine of green chemistry for the rapid production of AgNPs that act as a potential candidate to alleviate mastitis-causing bacteria and clear up diverse environmental problems. [ABSTRACT FROM AUTHOR]

Poly(N-isopropylmethacrylamide-co-methacrylic acid) [p(NipAam-Mac)] microgels were synthesized and used as microreactors to fabricate silver nanoparticles. Pure and hybrid microgels were characterized using Ultraviolet-Visible (UV/Vis) spectroscopy, Fourier transform infra-red (FTIR) spectroscopy and transmission electron microscopy (TEM). Catalytic activity of hybrid microgels and mechanism of catalysis by this system was explored using different reaction conditions. At the same temperature, apparent rate constant (kapp) was found to be varied from 0.0414 to 0.7852 min−1 by increasing the concentration of NaBH4 from 2.49 to 22.41 mM at constant concentration of substrate and catalyst. However upon extra increase in concentration of NaBH4 from 22.41 to 37.35 mM reduced the value of kapp to 0.2178 min−1. Likewise, the value of kapp was found to be increased from 0.1242 to 0.5495 min−1 with increasing the concentration of 4-nitrophenol [Para-nitrophenol (p-Np)] from 0.063 to 0.079 mM keeping other parameters constant. Further increase in concentration of p-Np caused decline in the value of kapp. Kinetic data reveals that catalytic reduction of p-Np obeys Langmuir-Hinshelwood mechanism and p-Np is converted to p-Ap on the surface of the silver nanoparticles passing through various reaction intermediates. [ABSTRACT FROM AUTHOR]

A really easy synthesis of Ag NPs with different shapes as spheres, triangles and disks were obtained from silver nitrate, sodium citrate and sodium borohydride in different stoichiometric amounts. Silver colloids with a variety of colors were obtained after irradiation for several hours with a homemade light source, from 400 to 715 nm. The evolution of plasmonic response was follows by UV-Vis spectroscopy and the morphology of Ag nanoparticles was determined by transmission electron microscopy. The procedure followed in this work results an alternative synthesis method of low-cost, modifiers-free, easy and simple to obtain Ag nanoparticles with different shapes and sizes. [ABSTRACT FROM AUTHOR]

This work reports a simple and one pot synthesis of water dispersible l-cysteine stabilized silver nanoparticles (l-CYS-AgNPs) in an acidic media. Silver nanoparticles were synthesized within few minutes of reaction time (< 5 min) at room temperature without needing to heat and use of any hazardous organic solvents. Prepared nanoparticles were characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction and zeta potential analysis, respectively. Surface plasmon resonance band of AgNPs which was observed at 392 nm by UV-Visible spectroscopy indicated successful formation of l-CYS-AgNPs in acidic media. Imaging techniques showed that AgNPs possess spherical morphology and average size of 25 nm. Nanoparticles were stable for more than 2 months when stored at ambient temperature. This approach is a facile and rapid one pot synthesis which can be stored as a homogenous aqueous dispersion for more than 2 months. Being stabilized by a sulfur-containing amino acid (l-cysteine) and the synthesis carried out in a moderately acidic media (pH 5.3) are distinctive aspect of this work. These stable l-CYS-AgNPs could be used as a catalyst and sensor applications for advanced perspective against water pollution and industrial effluents. [ABSTRACT FROM AUTHOR]

Simple rapid green synthesis route using Raphanus sativus leaf extract as reducing and stabilizing agent produced silver nanoparticles (Ag NPs) at room temperature. The formation of Ag NPs has been characterized and confirmed through TEM, XRD, FTIR and UV-visible absorption spectrum. Luminescence enhancement was observed only for few particular concentrations of Eu and Sm ions in Ag NPs. Enhancement of luminescence might be due to the increase in the electric dipole transition rate with the variation of local environment surrounding Ln ions. Lifetimes of Ln ions were found to increase with increase in Ag NP concentration to certain extent but found to decrease with further increase in Ag NPs. Nonlinear absorption behaviours in the picosecond (ps) and femtosecond (fs) time domains were studied by using the Z-scan technique. Third-order susceptibility was measured with ultrafast nonlinear optical response in the fs regime by using degenerate four-wave mixing (DFWM). High luminescence enhancement factors and good nonlinear optical properties of the biosynthesized Ag NPs have applications in biology and optics. [ABSTRACT FROM AUTHOR]

Herbal drugs prepared with the plant Ipomoea asarifolia has many medicinal uses throughout West Africa, including its employ as diuretic, emmenagogue and purgative. This species is a good source of acylated anthocyanins, and the methanol and ethyl acetate extracts of I. asarifolia are known for their strong acetylcholinesterase inhibitory effects. Here, green synthesis of Ag nanoparticles (Ag NPs) was performed at room temperature using the I. asarifolia leaf extract. The Ag NPs were characterized by UV-visible spectroscopy, FT-IR, XRD, AFM, SEM with EDX and TEM. AFM and SEM analyses showed that spherical morphology of I. asarifolia-synthesized Ag NPs with a size range of 20 to 60 nm. TEM revealed that I. asarifolia-synthesized Ag NPs had a mean particle size of 40 nm. The I. asarifolia-synthesized Ag NPs was tested against four bacterial pathogens using the disk diffusion method. The zone of inhibition varied significantly in a dose-dependent manner. Overall, our results underlined the potential of cheap aqueous extracts from this African medicinal plant species for the synthesis of silver nanocomplexes with wide efficacy against human pathogenic bacteria. [ABSTRACT FROM AUTHOR]

An eco-friendly, green synthesis of silver nanoparticles (SNPs) employing the fruit extract of Bridelia retusa was investigated. The UV-visible spectrum showed the surface plasmon peak at 436 nm, a characteristic feature of SNPs. SEM image showed spherical nanoparticles and EDX evidenced the presence of metallic silver with a strong signal for silver atoms at 2.98 keV. XRD patterns verified the crystalline nature of the SNPs which depicted a sharp peak at 38.52° corresponding to (111) plane and the average crystallite size was determined as 22.48 nm. Fourier Transform Infrared spectroscopic analysis confirmed the role of phenolic compounds in the synthesis and stabilization of nanoparticles. The average hydrodynamic diameter of the nanoparticles was 68.49 nm and their polydispersity index was 0.171 which corroborated the monodispersity. A high negative zeta potential value (−27 mV) provided the stability to the colloidal nanoparticle solution. The accelerated reduction of the Congo red dye in the presence of SNPs with a degradation rate constant of 0.056 min confirmed the catalytic potential of nanoparticles. Moreover, the synthesised nanoparticles inhibited the formation of blood clots in human blood samples which proved the anticoagulant activity and hence the nanoparticles can be used in nanomedicine. [ABSTRACT FROM AUTHOR]

A simple and green method was developed for the extracellular biosynthesis of silver chloride nanoparticles, free from silver nanoparticles, using cell-free filtrate of a thermotolerant fungal strain Aspergillus terreus 8. The synthesized silver chloride nanoparticles exhibited characteristic absorption maximum at 275 nm. As-fabricated AgCl-NPs were characterized by UV-vis spectroscopy, XRD, SEM-EDX, and FT-IR. The biosynthesized silver chloride nanoparticles exhibited strong antimicrobial activity towards pathogenic microorganisms such as Fusarium oxysporum f. sp. vasinfectum and Verticillium dahliae. The synthesized silver chloride nanoparticles can be exploited as a promising new biocide bionanocomposite against pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

The present study focused on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea (ground nut) root extract for the antibacterial and clinical application. The presence of major phytochemical compounds are found to be 2H-Pyaran,2,5-diethenyltetrahydro, Didodecyl phthalate, Decanoic acid, Tetradecanoic acid, Bis(2-ethylhexyl) phthalate, Dodecanoic acid, Phosphonic acid, 2-(4-Methoxyphenyl)-5-(4-methoxynaphthyl) thiophene and Methyl 2-(N-Benzylimino)-4-chloro-3,3-dimethylbutanoate by GC-MS. Nanoparticles synthesis is confirmed by UV-Vis analysis by observing the maximum absorption spectrum at 450 nm. XRD and SEM-EDX results reveals the synthesized nanoparticles are cubic crystalline with agglomerated particles of silver oxide with biomolecules present around it. TEM images clearly shows that the biosynthesized nanoparticles are mostly spherical and irregular shaped with an average particles size of 30 nm. Highest susceptibility pattern of silver nanoparticle against Enterococcus sp. (35 ± 0.4 mm) which followed by Pseudomonas sp. (33 mm) and Staphylococcus aureus (29 mm). Green synthesized nanoparticles are coated over the commercially available clinical band aid cloth by dip coating method. Silver nanoparticle incorporated band aid cloth showed good antibacterial activity against the harmful bacteria which usually cause infection and interfere during wound healing. Our findings revealed that green nanoparticle has a good antibacterial action against harmful bacteria and showed good response for efficient clinical application. [ABSTRACT FROM AUTHOR]