Silver Nitrate Concentration Research Articles

Green Synthesis of Silver Nanoparticles Using Bellevalia Flexuosa Leaves Extract

Silver nanoparticles (AgNPs) have broad biocidal activities, and are widely employed as an active ingredient in antiseptic, anti-viral, and anti-inflammatory preparations. Green-synthesizing AgNPs would be a rapid, cheap, and environmentally friendly method of synthesis. The methanolic extract of the leaves of Bellevalia flexuosa Boiss. (Asparagaceae) was used for the green synthesis of the AgNPs. The effects of the pH and the concentration of silver nitrate (AgNO3) on the synthesis of the AgNPs were investigated. The AgNPs produced above pH 10, and 1 mM of AgNO3 resulted in lower hydrodynamic diameters. Ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction proved the formation of the AgNPs, with a face-centered, cubed geometry. Scanning electron microscopy images showed colloidal and well-dispersed nanoparticles. In addition, the antibacterial activities of the prepared AgNPs were assessed by optical densities (ODs) against Gram-positive bacteria (Enterococcus faecalis and Staphylococcus epidermidis) and Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Salmonella enterica). The broths of Gram-negative and Gram-positive bacteria that contained AgNPs, showed lower OD values compared to the controls. In conclusion, AgNPs were prepared using B. flexuosa methanolic extract, and showed antibacterial activity against the tested bacterial strains.

Effectiveness of Snail Slime in the Green Synthesis of Silver Nanoparticles

The development of green, low cost and sustainable synthetic routes to produce metal nanoparticles is of outmost importance, as these materials fulfill large scale applications in a number of different areas. Herein, snail slime extracted from Helix Aspersa snails was successfully employed both as bio-reducing agent of silver nitrate and as bio-stabilizer of the obtained nanoparticles. Several trials were carried out by varying temperature, the volume of snail slime and the silver nitrate concentration to find the best biogenic pathway to produce silver nanoparticles. The best results were obtained when the synthesis was performed at room temperature and neutral pH. UV–Visible Spectroscopy, SEM-TEM and FTIR were used for a detailed characterization of the nanoparticles. The obtained nanoparticles are spherical, with mean diameters measured from TEM images ranging from 15 to 30 nm and stable over time. The role of proteins and glycoproteins in the biogenic production of silver nanoparticles was elucidated. Infrared spectra clearly showed the presence of proteins all around the silver core. The macromolecular shell is also responsible of the effectiveness of the synthesized AgNPs to inhibit Gram positive and Gram negative bacterial growth.

Waterborne pathogens treatment using biosynthesized silver‐mordenite nanocomposites in aqueous propolis extracts: Characterization and antibacterial activity

This paper deals with the preparation of silver/mordenite nanocomposite using aqueous propolis extract along with different concentrations of silver nitrate. The study of the prepared samples' structural properties gave two possibilities for the nanocomposite formation process, and this was confirmed by the UV–visible absorption spectrum and the energy‐dispersive X‐ray spectroscopy. Unexpectedly, the decrease in the size of these nanocomposites (14–21 nm) showed a non‐linear behavior with increasing silver nitrate concentration because of the presence of propolis during urbanization, and this was explained using the results of the transmission electron microscopy images and X‐ray diffraction. The Ag/mordenite nanocomposites showed the effective ability to eliminate the two types of bacteria (Gram‐positive [Staphylococcus aureus] and Gram‐negative [Escherichia Coli]). As well, these nanocomposites demonstrated with simple experiments the removal efficiency of some dyes pollutants (such as methylene blue, methyl orange, malachite green, indigo, and Congo red) from aqueous solutions. These results were explained in this article.

Antibacterial activity of silver nitrate on Pseudomonas aeruginosa bacteria using Calvet calorimetry

This study aimed to use microcalorimetry to analyze the real-time effect that silver nitrate has on one of the most common bacteria involved in severe infections in current medical practice. Using a Calvet microcalorimeter, the heat output produced by Pseudomonas aeruginosa was determined when exposed to concentrations of silver nitrate from 0 to 3 mol⋅m−3, and a saturated solution. Under physiological human body temperature, for 46 h, thermographic curves were obtained. The maximum voltage peaks (Vmax) and the total amount of heat exchanged (Q) were determined. The results showed a bactericidal effect, with a minimum inhibitory concentration (MIC) of silver nitrate of 0.75 mol⋅m−3, showing a Vmax of 93 μV and Q of 193 kJ. With higher concentrations of this metallic solution, the results highlighted the proportional negative effect that silver nitrate has in Pseudomonas aeruginosa growth.

Synthesis of silver nanoparticles fabricated by leaf extract of Caryota urens and its antioxidant activity

Many studies have been suggested that nanotechnology effects on various science fields. This study was instantiates leaf broth for synthesis of silver nanoparticles. The various physicochemical parameters viz., pH, incubation period, temperature, quality and quantity of leaf extracts and, silver nitrate concentration were influences synthesis of the phyto engineered nanoparticles. Secondary metabolites were present in leaf extract play an important role in the green reduction of the silver ions involved in the capping of the AgNPs during synthesis this study revealed from the FTIR spectroscopic studies. pH 10 influences the formation of brown color and bioreduction of Ag+ to Ag ions observed in surface Plasmon resonance bands developed by UV-Vis spectroscopic studies data revealed that 419 nm. The negative charged particles study revealed by zeta potential. The XRD study reveals that crystalline nature of the nanoparticles and, smallest size of the nanoparticles at highly purity at 2θ 380, lattice peak 111 and 15 nm. The peak was 1383 cm-1 mainly involving the aromatic ring involved In the capping of the AgNPs during phytoreduction. Atomic force microscopic and HR-TEM image reveal that spherical shape and size of the NPs. The size of the nanoparticles is 10-80 nm in scale. Formation of nanofringes describes the high stability in nature. The efficacy of silver nanoparticles on antioxidant activity eas determined by the DPPH assay at different concentrations viz., 12.5, 25, 50, 100, 200 and 400 μg/ml. This investigation revealed that the significant decrease the colour intensity of the reaction mixture, when compared to the standard ascorbic acid. The determined IC50 value of the silver nanoparticles was 50 μg/ml. These results were showed that a significant role in the increasing the radical scavenging activity.

Green Synthesis of Silver Nanoparticles Using Pecan Nut (Carya illinoinensis) Shell Extracts and Evaluation of Their Antimicrobial Activity.

Nowadays, the increase in bacteria resistant to multiple antibiotics has become a real threat to the human health, forcing researchers to develop new strategies. Silver nanoparticles (AgNPs) may be a viable solution to this problem. The green synthesis of AgNPs is considered a green, ecological and low-priced process that provides small and biocompatible nanostructures with antimicrobial activity with a potential application in medicine. In this work, pecan nut shell extracts were analyzed in order to determine their viability for the production of AgNPs. These NPs were synthesized using an extract rich in bioactive molecules, varying the reaction time and silver nitrate (AgNO3) concentration. AgNPs production was confirmed by FT-IR, UV-Vis and EDX spectroscopy, while their morphology and size were determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The antibacterial activity of AgNPs was evaluated by the agar diffusion method against Salmonella typhi, Staphylococcus aureus and Proteus mirabilis. The results showed that it is possible to obtain nanoparticles from an extract rich in antioxidant molecules with a size between 39.9 and 98.3 nm with a semi-spherical morphology. In addition, it was shown that the reaction time and the concentration of the precursor influence the final nanoparticles size. Antimicrobial tests showed that there is greater antimicrobial inhibition against Gram-negative than Gram-positive microorganisms, obtaining inhibition zone from 0.67 to 5.67 mm.

Study on the influence factors of silver powders size was prepared by liquid-phase reduction method

Quasi-spherical silver was synthesized by reducing silver nitrate with ascorbic acid by the liquid-phase reduction method. The effects of the concentration of silver nitrate and ascorbic acid, feed rate, and pH on the particle size of the silver powder were studied. The best conditions for preparing silver powder by the orthogonal experiment are: silver nitrate concentration is 0.05 mol/L, feeding speed is 25 mL/min and pH = 6. The morphology of the silver powder prepared under the optimal conditions is spheroidal, uniformly dispersed, and the particle size is 1.81 μm. Silver nitrate concentration is the most influential in powders' size silver powder.

THE ANTI-ASPERGILLUS POTENTIAL OF OPTIMIZED BIOSYNTHESIZED REDUCED GRAPHENE OXIDE/SILVER NANOCOMPOSITE USING ESCHERICHIA COLI D8 (MF062579)

Conventional antifungal agents have failed to treat several infectious diseases of many Aspergillus strains. These strains have been linked to the production of high-potency mycotoxins, which cause mould diseases on fruits and vegetables and have negative health consequences. The current study aimed to develop new effective nanomaterials using efficient methods that were stable and antifungal. The current work has been carried out to use the free cell supernatant of Escherichia coli D8 (MF062579) in the biosynthesis of reduced graphene oxide/silver nanocomposite (rGO/AgNC). At room temperature, the nanocomposite was prepared by an economical and simple one-step approach. Different parameters were optimized in the biofabrication of rGO/AgNC such as silver nitrate concentration, bacterial supernatant concentration, pH value, and temperature. Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Zeta analyses were used to evaluate the optimized rGO/AgNC. The biosynthesis process was performed within minutes in the incidence of solar irradiation. The mean size of silver nanoparticles (AgNPs) was estimated to be 9-18 nm. The biogenesis of spherical-shaped, well-dispersed AgNPs was validated by TEM images. AgNPs have a positive potential value, as seen by the zeta potential graph. rGO/AgNC had a harmful effect on the ultrastructure of rGO/AgNC-treated Aspergillus including membranes damage, malformation, and complete lysis of fungal cells in addition to enzymatic inhibition in lactate dehydrogenase activity. This study states a well-designed approach to develop a new antimicrobial agent, rGO/AgNC, against pathogenic human and phytopathogenic Aspergillus spp. in addition to a probable mechanism for the nanomaterial’s antimicrobial action.

Silver-Nanoparticle- and Silver-Nitrate-Induced Antioxidant Disbalance, Molecular Damage, and Histochemical Change on the Land Slug (Lehmannia nyctelia) Using Multibiomarkers.

It is known that silver nanoparticles (Ag NPs) and AgNO3 have harmful effects on the surrounding organisms, which may cause damage to these organisms. Therefore, the aim of this study is to detect damage caused by Ag NPs and silver nitrate to land slugs (Lehmannia nyctelia). In this study, the slugs were exposed to various concentrations of Ag NPs and AgNO3 for 15 days. The biochemical, antioxidant, lipid peroxidation (LPO), DNA fragmentation, and histopathological endpoints were assessed after 15 days of exposure to different concentrations of Ag NPs (0.04, 0.08, 0.4, and 0.8 g/L) and silver nitrate (0.04, 0.08, 0.4, and 0.8 g/L). The results show a significant decrease in total protein, total carbohydrate, superoxide dismutase, and GST and a significant increase in total lipid, LPO, and DNA fragmentation after exposure to Ag NPs and AgNO3 for 15 days compared with the control group. Histopathiological alterations were observed in the digestive glands which were indicated by histochemical staining. We concluded that exposure to AgNO3 and Ag NPs caused oxidative stress, genetic damage and alterations in the profile of muscle proteins and histological structure in L. nyctelia.

Synthesis and antibacterial potential of Loranthus pulverulentus conjugated silver nanoparticles.

The green method is not only harmonious to our environment but saves time and is comparatively cheaper than other methods. The current study is aimed to synthesize the silver nanoparticles (AgNPs) using the green method by using the leaves of Loranthus pulverulentus Wall (LPW) which functioned as a reducing as well as capping agent. The synthesis of biogenic AgNPs was confirmed by UV-Vis spectroscopy (UV-Vis.), Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), and Fourier transform infrared (FTIR). The absorbance maxima of the synthesized AgNPs were observed in the range of 405-435 nm. The SEM was used to find out the size and shape of the synthesized AgNPs, which revealed that the NPs were rectangular having sizes from 05 to 16 nm. XRD revealed that the synthesized NPs were crystalline and face-centered cubic (FCC). EDX analysis reflected the elemental composition of the synthesized product and showed that the percentage of silver=92. FTIR was used to confirm the functional groups responsible for the reduction and stabilization of silver ions. It revealed that biomolecules present in plant extract were responsible for the reduction and stabilization of silver ions. The effect of temperature, pH, reaction time, silver nitrate concentration, and plant extract concentration on the synthesis of AgNPs were also investigated. The synthesized silver nanoparticles were tested against four bacterial strains which showed strong antibacterial activity. We conclude that biogenic silver nanoparticles could be used as antibacterial agents to treat various diseases. RESEARCH HIGHLIGHTS: Loranthus pulverulentus Wall leaf extract mediated synthesis of silver nanoparticles. Effects of pH 3, 4, 6, 9, and 11, reaction time 5, 10, 20, 40 min, 1, 2, and 3h, temperature 30, 40, 50, 60°C, silver nitrate concentration 0.5, 1.0, 2.0, and 3.0 mM and plant extract concentration 0.5, 1.0, 2.0, and 3.0g on the AgNPs synthesis were also studied Scanning electron microscopy analysis revealed a small size of synthesized silver nanoparticles (8nm). The synthesized silver nanoparticles were found effective against various bacterial pathogens.

Green synthesis of silver nanoparticles using medicinal plants: Characterization and application

Nanotechnology has marked a significant revolution in various areas of science. Nanoscience and nanotechnology are involved in the production and application of nanoparticles that can be used in various fields. Silver nanoparticles (AgNPs), among other nanoparticles, have received substantial attention because of their unique properties. This review article focuses on the green synthesis of AgNPs using medicinal plant extracts. Green synthesized AgNPs offer numerous advantages, including energy efficiency, low toxicity, high yields, cost-effectiveness, eco-friendliness, and ready availability. The effects of pH, temperature, incubation time, light and plant extracts, and silver nitrate (AgNO3) concentrations on the green synthesis of AgNPs are discussed. This review also discusses analytical techniques for the characterization of AgNPs. Furthermore, recent advances in the application of biosynthesized AgNPs from herbal plants as therapeutic agents against bacteria, fungi, and tumors are considered. Finally, the challenges and potential future research directions for the synthesis of AgNPs using green technology are discussed.

Green Synthesis of Silver Nanoparticles Using Ocimum tenuiflorum Leaf Extract and its Antimicrobial Activity against Certain Pathogens

Nanoparticles (NPs) are particles less than 100 nm in size. Silver nanoparticles have many important chemical and biological applications. These applications drag the attention of researchers for the production of silver nanoparticles. The objective of the study is to synthesize silver nanoparticles from the green method without using any hazardous chemicals. In the present study, Ocimum tenuiflorum (Tulsi) leaf extract was used to synthesize silver nanoparticles (Ag-NPs) from silver nitrate. Moreover, Tulsi leaf extract was also exploited, both traditionally and commercially, for their antibacterial potential which is essential oil components. The synthesis of Ag-NPs was visually deduced by a change in colour from light yellow to reddish-brown. UV-Visible Spectrometry, X-ray diffraction (XRD), and Transmission Electron Microscopic (TEM) analysis were then used to characterize synthesized nanoparticles. This study also determined the effect of temperature and effect of silver nitrate concentration on nanoparticle synthesis. Synthesized silver nanoparticles showed absorbance ‘peaks’ at 420 nm with UV-visible spectrometry. X-ray diffraction studies showed that the synthesized silver nanoparticles were crystalline. The mean crystallite size was estimated using the Debye-Scherrer equation. However, TEM showed that silver nanoparticles have spherical (40 nm) shape with a narrow size distribution. These synthesized nanoparticles were used to evaluate antimicrobial activity against the most common pathogens of nosocomial infections, MRSA, E. coli, Salmonella typhi, and Klebsiella pneumoniae (ESBL). O. tenuiflorum extract showed strong potential for the synthesis of silver nanoparticles from silver nitrate and the synthesized silver nanoparticles had efficient antimicrobial properties against different pathogens including drug-resistant pathogens in vitro. These synthesized nanoparticles showed maximum ‘zones’ of inhibition against MRSA among these four organisms.

The Influencing Effect of Silver Nitrate Fillers on the hardness of Flexible Resin

The development of polymer chemically produces alternative materials to polymethyl methacrylate, such as nylon, and epoxy resin, these resins are modified by thermoplastic process, and This Received The disadvantage of acrylic resin is the colonization of microorganism growth of fungi and candida adhesion. This study is designed to evaluate and compared the consequence of silver nitrate fillers reinforcement Accepted flexible acrylic hardness as one of the mechanical properties to find the effect of various concentrations. A (0.1and 0. 2) ml of the filler (silver nitrate) additive to the flexible acrylic. Forty five (45) specimens were prepared for testing in this study. The hardness test was used in this study. The sample of this test was divided into (3) groups (control group) and experimental groups as follows: Group A= (15) specimens without silver nitrate (Control group 0% silver nitrate). Group B= (15) specimens with (0.1 ml) silver nitrate. Group C= (15) specimens with (0.2 ml) silver nitrate. All control and test groups were processed; curred then finished and polished the specimens ready for testing. Shore A test against the concentration of silver nitrate the result of this study showed a high significant increase in the mean value of hardness for control groups to the silver nitrate compared with experimental groups.

Impact of silver nanoparticles on multiplication, rooting of shoots and biochemical analyses of date palm Hayani cv. by invitro

Nano silver has positive effects on the growth and development of in vitro plants. The current study was carried out to investigate the effect of adding different concentrations of nano silver nitrate (0.0, 1.0, 2.0, 3.0 and 4.0 ml/l) to the culture medium in multiplication and rooting stage of the date palm cv. Hayani. The results showed that there was a significant difference of Ag NPs concentrations in regeneration stage as it increased the number and length of shoots at 3.0 ml/l concentrations compared to the control treatment. The outcome of shoots multiplication experiment indicated that Ag NPs concentration had a significant positive effect on studied traits, when the 3.0 ml/l of Ag NPs added to MS basal medium supplemented with BA at 2.0, GA3 at 0.5 and NAA at 0.1 (mg/l) gave the highest shoots and leaves number as it reached 10.74 shoots and 30.11 leaf/culture with length 6.60 cm, respectively in comparison with lowest results recorded 2.50 shoot/culture, 10.70 leaf/culture with length 2.00 cm, respectively with the control treatment. All shoots were cultivated in a new medium supplemented with NAA at 1.0 mg/l and various concentrations of Ag NPs to study root formation. The findings indicated that the optimal medium for root formation was one that included Ag NPs at 3.0 ml/l which resulted in the highest rooting percentage (85.4%), root number (8.4 root/culture) with length 6.3 cm. In concentration 3.0 ml/l of Ag NPs recorded that, chlorophyll A, chlorophyll B and carotenoids increases to 1.50, 1.10 and 2.33 (mg/g). Also, occurred increase in carbohydrate content to 26.33 mg/g, the proline was enhanced and increased gradually to 3.31 mg/g and protein content to 0.77 mg/g.

Green Synthesis of Silver Nanoparticles Using Aqueous Citrus limon Zest Extract: Characterization and Evaluation of Their Antioxidant and Antimicrobial Properties.

The current work concentrated on the green synthesis of silver nanoparticles (AgNPs) through the use of aqueous Citrus limon zest extract, optimizing the different experimental factors required for the formation and stability of AgNPs. The preparation of nanoparticles was confirmed by the observation of the color change of the mixture of silver nitrate, after the addition of the plant extract, from yellow to a reddish-brown colloidal suspension and was established by detecting the surface plasmon resonance band at 535.5 nm, utilizing UV-Visible analysis. The optimum conditions were found to be 1 mM of silver nitrate concentration, a 1:9 ratio extract of the mixture, and a 4 h incubation period. Fourier transform infrared spectroscopy spectrum indicated that the phytochemicals compounds present in Citrus limon zest extract had a fundamental effect on the production of AgNPs as a bio-reducing agent. The morphology, size, and elemental composition of AgNPs were investigated by zeta potential (ZP), dynamic light scattering (DLS), SEM, EDX, X-ray diffraction (XRD), and transmission electron microscopy (TEM) analysis, which showed crystalline spherical silver nanoparticles. In addition, the antimicrobial and antioxidant properties of this bioactive silver nanoparticle were also investigated. The AgNPs showed excellent antibacterial activity against one Gram-negative pathogens bacteria, Escherichia coli, and one Gram-positive bacteria, Staphylococcus aureus, as well as antifungal activity against Candida albicans. The obtained results indicate that the antioxidant activity of this nanoparticle is significant. This bioactive silver nanoparticle can be used in biomedical and pharmacological fields.

Efficient photoelectrocatalytic conversion of CO2 to formic acid using Ag-TiO2 nanoparticles formed on the surface of nanoporous structured Ti foil

Global warming and adverse climate change, which have been intensified by a strident increase in carbon dioxide (CO2) emissions, have necessitated the development of alternative techniques to reduce the disproportionate concentration of CO2 in the atmosphere. The photoelectrochemical reduction of CO2 is a technique of lowering the energy required to convert greenhouse gases into useful end products. Herein, we have manufactured an innovative, cost-effective silver (Ag) decorated anatase TiO2 (TO-Agx; ‘x’ stands for different concentration of Ag) nanoparticles which created on the 3D nanoporous structured surface of a thin titanium foil (Ti-foil) by the assist of chemical treatment with hydrogen peroxide (H2O2) and different concentrations (1, 5, 10, 20 mM) of silver nitrate (AgNO3) solution and followed by calcination at 500 °C. As-prepared samples were analyzed by several characterization techniques such as XRD, XPS, TEM and Raman spectroscopy. Among various samples (TO, TO-Ag1, TO-Ag5, TO-Ag20), the TO-Ag10 sample were exposed a supreme photocurrent density of 83.2 µA/cm−2 (86.1% higher than TO sample which is untreated with AgNO3 solution). Because of its high photocurrent density, the sample TO-Ag10 were selected as the electrode material for photoelectrochemical CO2 reduction reaction and a lowest reduction onset potential (−1.018 V) was observed on linear sweep voltammetry analysis in the presence of light with Ag/AgCl reference electrode. 1H NMR analysis of the product solution exposed the production of formic acid as a single product of CO2 reduction reaction after the chronoamperometric electrolysis were carried out more than 6 h. The maximum faradaic efficiency (73%) and formic acid yield (193 µmol cm−2 h−1) were found at an applied potential of −1.2 V (vs. Ag/AgCl reference electrode) for TO-Ag10 photocathode.

Therapeutic potential of biogenic and optimized silver nanoparticles using Rubia cordifolia L. leaf extract

Rubia cordifolia L. is a widely used traditional medicine in the Indian sub-continent and Eastern Asia. In the present study, the aqueous leaf extract of the R. Cordifolia was used to fabricate silver nanoparticles (RC@AgNPs), following a green synthesis approach. Effect of temperature (60 °C), pH (8), as well the concentration of leaf extract (2 ml) and silver nitrate (2 mM) were optimized for the synthesis of stable RC@AgNPs. The phytofabrication of nanosilver was validated by UV–visible spectral analysis, which displayed a distinctive surface plasmon resonance peak at 432 nm. The effective functional molecules as capping and stabilizing agents, and responsible for the conversion of Ag+ to nanosilver (Ag0) were identified using the FTIR spectra. The spherical RC@AgNPs with an average size of ~ 20.98 nm, crystalline nature, and 61% elemental composition were revealed by TEM, SEM, XRD, and. EDX. Biogenic RC@AgNPs displayed a remarkable anticancer activity against B16F10 (melanoma) and A431 (carcinoma) cell lines with respective IC50 of 36.63 and 54.09 µg/mL, respectively. Besides, RC@AgNPs showed strong antifungal activity against aflatoxigenic Aspergillus flavus, DNA-binding properties, and DPPH and ABTS free radical inhibition. The presented research provides a potential therapeutic agent to be utilized in various biomedical applications.

Synthesis of Silver Nanoparticles Using Premna serratifolia Linn. Leaf Extract as Reducing Agent and Their Antibacterial Activity

Premna serratifolia Linn. leaf extract has been used as a reducing agent in the synthesis of silver nanoparticles (AgNPs). Various synthesis parameters such as reaction time, concentration and the pH of the Premna serratifolia Linn. leaf extract, and silver nitrate concentration were investigated. In addition, the stability of synthesized AgNPs and their activity against Staphylococcus aureus and Escherichia coli have also been investigated. The results of the experiment showed that Premna serratifolia Linn. leaf extract reduced silver ions resulting in AgNPs. In addition, the AgNPs colloid showed a gradual change in color from transparent green to yellow. At the same time, its ultraviolet (UV)-Visible spectra exhibited the typical surface plasmon resonance peak at around 400-415 nm. The optimum reaction conditions in the formation of AgNPs are 40 minutes of reaction time using silver nitrate 1.5x10-4 M and Premna serratifolia Linn leaf extract 80 ppm at pH 10. The particle size of synthesized AgNPs distributes from 48.3-157 nm with an average size of 58.7±14.4 nm and is stable at least for 1- month storage under ambient conditions. The antibacterial test shows that synthesized AgNPs are effective against both Escherichia coli and Staphylococcus aureus.

Green synthesis and characterization of silver nanoparticles using Eugenia roxburghii DC. extract and activity against biofilm-producing bacteria

The green synthesis of silver nanoparticles (AgNPs) and their applications have attracted many researchers as the AgNPs are used effectively in targeting specific tissues and pathogenic microorganisms. The purpose of this study is to synthesize and characterize silver nanoparticles from fully expanded leaves of Eugenia roxburghii DC., as well as to test their effectiveness in inhibiting biofilm production. In this study, at 0.1 mM concentration of silver nitrate (AgNO3), stable AgNPs were synthesized and authenticated by monitoring the color change of the solution from yellow to brown, which was confirmed with spectrophotometric detection of optical density. The crystalline nature of these AgNPs was detected through an X-Ray Diffraction (XRD) pattern. AgNPs were characterized through a high-resolution transmission electron microscope (HR-TEM) to study the morphology and size of the nanoparticles (NPs). A new biological approach was undertaken through the Congo Red Agar (CRA) plate assay by using the synthesized AgNPs against biofilm production. The AgNPs effectively inhibit biofilm formation and the biofilm-producing bacterial colonies. This could be a significant achievement in contending with many dynamic pathogens.

Synthesis of silver nanoparticles by atmospheric pressure plasma jet

Silver nanoparticles are one of the most extensively used metallic nanomaterials due to their unusual physical and chemical properties as well as their promising applications in a wide range of different fields. In this study, a non-thermal atmospheric pressure helium plasma jet was used to successfully synthesize silver nanoparticles with silver nitrate as a precursor and trisodium citrate as a capping agent. The browning of the solution after only 5 min of plasma irradiation is a result of the surface plasmon resonance (SPR) from the obtained silver nanoparticles. The SPR was confirmed by the presence of an absorption band in the visible range between 400 and 450 nm demonstrated in the UV–vis spectra. The effect of different chemical parameters such as the concentration of silver nitrate and the concentration of citrate on the silver nanoparticles have been studied. These nanoparticles were further characterized using transmission electron microscopy and dynamic light scattering. Therefore, the plasma jet was advantageous to fast produce silver nanoparticles in friendly conditions. In addition, the used experimental setup allows further studies in different solvents conditions and with different capping agents. So, this methodology could be useful for the preparation of silver nanoparticles required for numerous applications such as bioactivity, catalysis, surface enhanced Raman scattering, and photonic.