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Soft gamma ray irradiation is done on Silver nano colloids prepared using Pepper Nigrum as reducing and stabilizing agent. Change in surface morphology and the structure of the colloid is obtained from Transmission Electron Microscope images and Selected area Electron Diffractogram. Morphology of the gamma irradiated sample is devoid of nano particle clusters and the Selected Area Electron Diffraction pattern confirms the crystal nature as face centered cubic structure of nano silver. UV–visible spectroscopic analysis gives the absorption peaks in the green region. Gamma irradiation results in the reduction in peak intensity without any change in wavelength. A statistical approach is done on treating the gamma irradiated colloidal sample with the as prepared silver nano colloid for measuring the area of affecting fungal infection on a potato-agar medium. It is found that the fungal growth is declined rapidly with the introduction of gamma irradiated silver nano colloid than the as prepared colloid.

The possibility of printing conductive ink on textiles is progressively researched due to its potential benefits in manufacturing functional wearable electronics and improving wearing comfort. However, few studies have reported the effect of conductive ink formulation on electrodes directly screen-printed on flexible substrates, especially printing UV curable conductive ink on common textiles. In this work, a novel UV curable nano-silver ink with short-time curing and low temperature features was developed to manufacture the fully flexible and washable textile-based electrodes by screen printing. The aim of this study was to determine the influence of ink formulation on UV-curing speed, degree of conversion, morphology and electrical properties of printed electrodes. Besides, the application demonstration was highlighted. The curing speed and adhesion of ink was found depending dominantly on the type of prepolymer and the functionality of monomer, and the type of photoinitiator had a decisive effect on the curing speed, degree of double bond conversion and morphology of printed patterns. The nano-silver content is key to guarantee the suitable screen-printability of conductive ink and therefore the uniformity and high conductivity of textile-based electrodes. Optimally, an ink formulation with 60 wt% nano-silver meets the potential application requirements. The electrode with 1.0 mm width showed significantly high electrical conductivity of 2.47 × 106 S/m, outstanding mechanical durability and satisfactory washability. The high-performance of electrodes screen-printed on different fabrics proved the feasibility and utility of UV curable nano-silver ink. In addition, the application potential of the conductive ink in fabricating electronic textiles (e-textiles) was confirmed by using the textile-based electrodes as the cathodes of silver-zinc batteries. We anticipate the developed UV curable conductive ink for screen-printing on textiles can provide a novel design opportunity for flexible and wearable e-textile applications.

In the present study silver nano-particles were synthesised by green synthesis method using fenugreek leaves extract, provides necessary bioactive for reduction of silver ions to silver nanoparticles. The sharp bands of silver nanoparticles were observed around 432 nm. Synthesis process was further optimized for pH, extraction temperature, Ag ion concentration, extract volume and extraction time on the basis of absorbance and average particles size respectively. FTIR analysis showed presence of corresponding peaks of O–H stretching and N–H amide groups. FESEM images revealed the structure and morphology of spherical AgNPs of average size 30 nm. The antibacterial activity of thus synthesized AgNPs was then tested against S. aureus, E. coli, P. aeruginosa and V. cholera and found synthesized AgNPs have higher inhibitory action against P. aeruginosa compared to other bacteria. The larger size of nano-particles is less active than smaller size of nano-particles due to small surface area.

In the current study, an efficient method was developed for the preparation of phenothiazinium Schiff base ligand followed by the attachment to nanosilver mediated by egg white (lysozyme) as a catalyst and reductant under solvent-free conditions. The synthesized Schiff base ligand, nanosilver, and its complex were characterized by UV, IR, XRD, and NMR. Biological studies for Schiff base ligand, nanosilver, and its complex were investigated. The advantages of this method are environmentally benign process; the product can be isolated simply by filtration, simplicity, elimination of solvents, high product yields, and short reaction times. The synthesized compounds were tested for their in vitro antimicrobial activity using the broth dilution method against Staphylococcus aureus (gram-positive) and E. coli (gram-negative) bacteria. From the results the silver nanocomplex exhibits enhanced antibacterial activity which may be due to the interaction of Schiff base and nano Ag on the bacterial cell wall. The silver complex can be utilized in the future for drug delivery and biomedical applications.

Graphical abstract, Highlights • Nano-silver synthesized via solution evaporation method with octahedral crystal structure and crystallite size of 28 to 39 nm. • Irregular and non-uniform surface morphology. • Different functional on the surface of nano-silver included CH, CH2, OH, alkyne, and an alkyl halide. • Nano-silver synthesized at 70 °C and a dose of 3.0 g/L caused effective inhibition of E. coli., The modulation of antimicrobial properties of nanomaterials can be achieved through various physical and chemical processes, which ultimately affect subsequent properties. In this study, the antibacterial potential of nano-silver was investigated at 0.5, 1.0, 2.0, and 3.0 g/L, and its differential temperature synthesis was achieved at 20, 50, and 70 °C using the solvent evaporation method. Nano-silver particles exhibited FCC (octahedral) crystalline structure with crystallite sizes ranging between 28 and 39 nm calculated using XRD analysis. Moreover, irregular and non-uniform surface morphology was evident from SEM micrographs. The UV–Vis absorbance spectrum of nano-silver exhibited wave maxima at 433 nm, while the FTIR analysis depicted different modes of vibration indicating the CH, OH, C≡C, C-Cl, and CH2 functional groups attached to the surface. Lastly, nano-silver caused prominent inhibition (12.5 mm) in the Escherichia coli growth, particularly at 70 °C synthesis temperature and 3.0 g/L dose. It is concluded that both the nano-silver crystal growth temperature and dose contributed substantially to bacterial growth inhibition linked with subsequent size, shape-dependent properties.

Improving the immunity of COVID-19 patients is very important for the healing process. As is known, viral diseases, including COVID-19, cannot be treated. What can be done is to increase the body's immune system to be strong against the virus attack and weaken it. Various efforts to increase immunity are carried out, among others, with Moringa capsules containing nanogold and nano-silver. Nanogold as drug delivery and nano-silver as antiviral. A total of 64 COVID-19 patients who were treated using Moringa capsules routinely showed a significant recovery process. Clinical trial volunteers were grouped into 3 categories. The first group of positive COVID-19 asymptomatic 22 people. The second group of 24 COVID-19 positive people with mild to moderate symptoms, including experiencing fever, cough, runny nose, and weakness. The 3rd group of 18 people were COVID-19 patients with severe conditions with respiratory problems to the point of using a ventilator. The results of the clinical trial showed that the first group of Covid-19 patients recovered after consuming Moringa capsules for 1-2 weeks, the second group recovered 3-6 weeks. The 3rd group recovered 4-8 weeks. In conclusion, it is proven that Moringa capsules with nanogold and nano-silver increase the immunity of Covid-19 patients so that they survive and recover from their pain. The length of time required for recovery is different for each group. The first group recovered faster than the second group. The third group recovered the longest. It is highly recommended to use Moringa capsules with nanogold and nano-silver innovations to recover COVID-19, especially the new variants that are more easily spread.

Pyrolysis gasoline (Py gas) is used as an octane enhancer of gasoline as it is rich in aromatics. However, removal of carcinogenic benzene from Py gas before blending with gasoline is important to meet the fuel specifications. The main focus of this present study is to determine the sorption kinetics and sorption isotherm of a fabricated insitu nano silver/polyvinyl alcohol (insitu nano Ag/PVA) membrane for pervaporative separation of benzene from model Py gas [mixture of benzene (aromatic) and 1-octene (aliphatic)]. The thickness, surface morphological structure (Atomic Force Microscopy) and degree of swelling of the fabricated membrane were determined. The highest pervaporation separation index achieved for the selected system was 14.259 kg/m2/h at 303 K, with 30 volume% benzene in model Py gas using a downstream pressure of 1 mm of Hg. The sorption kinetics of benzene in insitu nano Ag/PVA membrane obeyed the Elovich model while the Temkin isotherm model fitted the experimental data of the chosen system most accurately.

Purpose In flexible electronics applications, organic inks are mostly used for inkjet printing. Three-dimensional (3 D) printing technology has the advantages of low cost, high speed and good precision in modern electronic printing. The purpose of this study is to solve the high cost of traditional printing and the pollution emissions of organic ink. It is necessary to develop a water-based conductive ink that is easily degradable and can be 3 D printed. A nano-silver ink printed circuit pattern with high precision, high conductivity and good mechanical properties is a promising strategy. Design/methodology/approach The researched nano-silver conductive ink is mainly composed of silver nanoparticles and resin. The effect of adding methyl cellulose on the ink was also explored. A simple 3 D circuit pattern was printed on photographic paper. The line width, line length, line thickness and conductivity of the printed circuit were tested. The influence of sintering temperature and sintering time on pattern resistivity was studied. The relationship between circuit pattern bending performance and electrical conductivity is analyzed. Findings The experimental results show that the ink has the characteristics of low silver content and good environmental protection effect. The printing feasibility of 3 D printing circuit patterns on paper substrates was confirmed. The best printing temperature is 160°C–180°C, and the best sintering time is 30 min. The circuit pattern can be folded 120°, and the cycle is folded more than 60 times. The minimum resistivity of the circuit pattern is 6.07 µΩ·cm. Methyl cellulose can control the viscosity of the ink. The mechanical properties of the pattern have been improved. The printing method of 3 D printing can significantly reduce the sintering time and temperature of the conductive ink. These findings may provide innovation for the flexible electronics industry and pave the way for alternatives to cost-effective solutions. Originality/value In this study, direct ink writing technology was used to print circuit patterns on paper substrates. This process is simple and convenient and can control the thickness of the ink layer. The ink material is nonpolluting to the environment. Nano-silver ink has suitable viscosity and pH value. It can meet the requirements of pneumatic 3 D printers. The method has the characteristics of simple process, fast forming, low cost and high environmental friendliness.

The significant progress in efforts to design hydrogel adhesive mimicking mussels' functions has been witnessed in recent years. However, it is still an arduous challenge to fabricate self-adhesive hydrogel adhesive that tradeoff of exalting features containing scalability, self-healing, degradability, biocompatibility, and antibacterial properties. Herein, we manufactured a multi-functional physical hydrogel adhesive by integrating catechol groups modified chitosan and polyvinyl alcohol (PVA). Intriguingly, the physical gels reinforce durable and repeatable adhesiveness due to the limited auto-oxidation of catechol groups of the 3-(3,4-dihydroxyphenyl) propionic acid modified chitosan (DCS), which can be adhered diametrically on human skin without shedding and residue. Additionally, the dynamic H-bonds between DCS and PVA endows the hydrogel to self-heal under a relatively mild stimulation. The assembly of silver nano armor remarkably enhances the mechanical strength and antibacterial of the hydrogel. Meanwhile, the metal coordination formed between the nano-silver and the hydroxyl groups of catechol and the electrostatic interaction between the silver ions and the hydroxyl groups also contribute to the hydrogel to achieve self-healing. This work provides a neoteric prospect in designing degradable hydrogels with stretchability, self-adhesion, self-healing, antibacterial and biocompatibility for potential applications in tissue adhesion and wound healing.

Nano-silver (nAg), and silver ions (Ag+), present unique properties that present both opportunities and challenges for different environmental engineering applications, such as disinfection and wat...

The aim of this study was to optimize the preparation method of polymethyl methacrylate (PMMA) denture base loaded with nano silver (NAg), to more effectively and safely impart sustainable antibacterial functions. NAg solution was synthetized and mixed with acrylic acid and methyl methyacrylate (MMA) monomer in order to prepare a new type of NAg solution (NS)/polymer methyl methacrylate denture base specimens (NS/PMMA). The surface morphology, mechanical strength, antimicrobial activity, anti-aging performance, cytotoxicity and biocompatibility of NS/PMMA denture base were evaluated in comparison with specimens fabricated using traditional NAg adding methods and NAg-free denture base. The aesthetic characteristics and mechanical strength of NS/PMMA denture base met the clinical application requirements. Meanwhile, NS/PMMA denture base showed better antibacterial activity, anti-aging properties, no cytotoxicity and displayed exceptional biocompatibility. NS/PMMA denture base thus has great potential for clinical application.

Studied the silver nanoparticles antibacterial action when it coated titanium dental implants. The accumulation of nano-silver on implants surface obtained by scanning electron microscopy and energy dispersive X-ray spectroscopy. The distribution of nano silver is uneven throughout the entire length of the implant. Nano silver is scattered over the surface of the implant with a particle size of up to 5 nM.

In the current study, layerwise theory (LT) was used to calculate thermal stresses in a clamped rectangular composite plate with nano-silver coating subjected to an external voltage. The composite ...

The development of scalable, biocompatible, cost effective, and simple techniques for silver nanoparticles (AgNPs) synthesis is one of the significant fields in Nanoscience research. Hence, in this study, the green chemicals present in the Pandanus amaryllifolius Roxb. leaves were extracted by using the Soxhlet extraction apparatus. Pandanus amaryllifolius Roxb. leaves extract composed of Catechin, Gallic acid, Indole, Benzyl acetate, and Cresol, which can be used in the reduction of silver ions (Ag+) into nano silver (Ag0). The preliminary preparation of AgNPs was observed by color change to brown and it is further characterized by UV-Vis, FT-IR, SEM, XRD, TGA and DTA studies. The cytotoxicity activity of Pandanus amaryllifolius Roxb. leaves-silver nanoparticles (PARLE-AgNPs) was tested on cancer cell lines. Interestingly, the synthesized PARLE-AgNPs exhibited robust anticancer activity against both lung cancer (A549) and breast cancer (MCF7) cell line and results are compared with standard cisplatin drug. The IC 50 of cell inhibition of PARLE-AgNPs against MCF-7 & A549 cell lines was found to be 27.19 µg/ml and 22.36 µg/ml respectively. Quantum chemical studies confirm the electron donation property of Pandanus amaryllifolius Roxb. leaves extract. This greenly prepared silver nano-formulation has a huge potential to be explored in various diverse aspects.

The common polyol techniques were used for the synthesis of solo metallic morphology. Here we reported the single-step polyol-solvothermal strategy for the synthesis of zero, one, two, and three-dimension silver structure by simply switching the reaction pressure with the help of silver amount and halide ions. Silver seeds in the presence of Cl- ion, at 74.1 mmHg grow in [1 1 1] and at 97.4 mmHg grow in [1 1 0] direction for the formation of 0D-Ag and 1D-Ag respectively, by protecting (1 0 0) facet. Extra halide (Br-) presence at 93.2 mmHg imposes the seeds to grow [1 1 0], [1 0 0] direction for 2D-Ag, while at 97.4 mmHg grow only in [1 0 0] direction for 3D-Ag, due to etching and formation of single crystal seeds. This closed reaction system doesn’t need any kind of oxygen scavengers, inert gases, nor need to tune injection speed and stirring speed. This switching strategy can be implemented for the synthesis of other metallic morphologies.

In this present work, we have investigated the arsenic, fluoride and nitrate removal by the poly (ether-ether-sulfone) (PEES)/nano-silver hybrid membranes effectively prepared by the non solvent induced phase separation. The prepared membranes were characterized by thermal and mechanical properties to investigate the influence of nano-silver on the final properties of the membranes. Hence, our experimental study is based on arsenic (III) and arsenic (V) rejection studies attempted at different pH. The results of this study revealed the As (V) removal by NF with a high rejection of 99.98% compared to As (III). Fluoride and nitrate studies were carried out at neutral pH and it showed more than 80% rejection. Based on this investigation, it was concluded that the PEES/nano-silver membranes were effectively applicable to remove hazardous metal ions.

To prevent microbial contamination in foods and medical tools, we prepared a novel antibacterial material nano-silver loaded poly(styrene-co-acrylic) (nAg-PSA) composites by in situ reductions. The nAg-PSA was characterized by scanning electron microscope, transmission electron microscopy, energy dispersive X-ray spectroscopy and thermogravimetric analysis. The antibacterial properties of nAg-PSA against Escherichia coli and Staphylococcus aureus were systematically evaluated, and the underlying mechanism was investigated. Results showed that the silver nanoparticles were successfully loaded onto PSA microspheres, highly dispersed on the surface of nAg-PSA nanoparticles. The nAg-PSA nanoparticles all showed significant antibacterial effects, among which nAg-PSA4 had maximum diameters of inhibition zones against the Gram-negative E. coli (1.18 mm) and the Gram-positive S. aureus (1.29 mm), respectively, which closely related to the size and density of silver nanoparticles covered on the surface.

The effect of presence of silver nanoparticles in pure N-methyl-2-pyrrolidone (NMP) solvent for ethylene gas absorption in an experimental pressure decaying setup has been investigated. All experiments were performed at temperatures of 278.15 K, 298.15 K and 328.15 K and different pressures (up to ethylene dew point) as well as different concentrations of silver nanoparticles (0.05 g·L−1 and 0.1 g·L−1). The kinetic data of absorption, Henry's law constants, and heat of absorption were calculated. Comparison of the pure solvent and the nanofluids absorption results revealed that the presence of small amounts of nanoparticles could improve the absorption performance between 1.5% - 18%. Finally, the effect of temperature, pressure, and nanoparticle concentration on the equilibrium results were investigated.

The main aim of the present investigation is to develop and synthesis the precious nano-metals such as nano gold and its by product components such as nano copper, nano silver etc. The investigatio...

Aim: The aim of the present study was to investigate the antimicrobial effect of AH Plus and Ceraseal sealers with and without the incorporation of silver nanoparticles against Enterococcus faecalis using the direct contact assay. Methodology: Silver nanoparticles were prepared by chemical reduction method. Direct Contact Test (DCT) was carried out by settling 50mg of freshly mixed sealer in a sterile flat bottom screw capped tube.Ten tubes were prepared for each sealer in duplicate as follow:Group(I): Ceraseal (Meta Biomed Co., Cheongju, Korea) , Group (II): Ceraseal& Nano silver gel, Group(III): AH Plus (Dentsply/Maillefer, Konstanz, Germany) and Group (IV): AH Plus & Nano silver gel. Antibacterialactivity was evaluated against Enterococcus faecalis ATCC 35550 at various time intervals 1 ,24 and 168 hours,. Results: DCT results revealed that AH Plus had higher antibacterial activity against Enterococcus faecalis at different time intervals than Ceraseal sealer unaffected by (AgNPs)incorporation. But the incorporation of(AgNPs)significantly increased their antibacterial effect. All sealers had lost much of their antibacterial effects at 7 days interval. Conclusion: AH Plus sealer had higher antibacterial effect than Ceraseal sealer. Incorporation of (AgNPs) silver nanoparticles can improve the antibacterial activity of AH Plus and Ceraseal sealer.

In the modern years, there is an enlarged use of silver nanoparticles (SNPs) in industrial and in the field of medical practice significantly, still, their high risk and lethal outcome have not been studied considerably. The aim behind this research work was to incorporate silver nanoparticles (AgNPs) using Vernonia anthelmintic seeds extract and to assess its antibacterial activity. AgNPs were properly synthesized by the green method and the evolution of AgNPs was firmed by optical color change and UV (ultraviolet) spectroscopy. Synthesized AgNPs were decontaminated and characterized by using Silver Content Estimation-Inductive Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Zeta potentiometry, X-ray diffraction (XRD), and transmission electron microscopy (TEM). UV peak at 453.5 nm confirmed the formation of AgNPs. XRD studies disclosed the crystalline nature of AgNPs. ICP-AES studies showed the presence of silver in colloidal dispersion and images were recorded by using HRTEM. Synthesized AgNPs were found to be potent against Staphylococcus aureus, Pseudomonasaeruginosa, E. coli, and MRSA. However, these SNPs are cytotoxic in nature and could obey as a superior antibacterial for therapy of bacterial infections in this period of multiple drug defiance.

In this present study, biosynthesis of AgNp’s from methanolic extracts of H. Colorata and its wound healing activity was documented. The synthesis of AgNp’s was done by treating AgNO3 solution with an aqueous extract of H. colorata. The production of AgNp’s was confirmed by a color change of the solution from clear to brown color. The reduced AgNp’s were characterized by Scanning Electron Microscope (SEM), UV–vis spectroscopy. From UV analysis peak was observed at 415nm and spherical shaped AgNp’s were observed. The antibacterial activity and Minimum inhibitory Concentration (MIC) of the silver nanoparticles were determined. The results suggest that biosynthesized AgNp’s from aqueous extracts ofH.coloratashowed a significant antibacterial activity against wound pathogens.

Abolition of bleaching as a sequential step in functionalization of flax fibers is a quite important issue for diminishing of the treatment steps, saving energy, lowering the chemical consumption and consequently reducing the final cost. Therefore, herein, functionalization of the scoured flax fibers in one-pot process is systematically presented, via straightforward insertion of silver nanoparticles (AgNPs) using two different reduction methods including internal and external reduction. Ag+ was reduced by using the functional groups of flax in the internal reduction, while, trisodium citrate was used as an external reducing agent in the external reduction method. Functionalization was performed to acquire a decorative yellowish color, ultraviolet (UV) protection and antimicrobial properties for flax fibers. The formation of AgNPs within flax fibers was confirmed by absorbance spectra, color data, carboxyl and aldehyde contents. Silver contents onto fibers was ranged in 4.9–11.8 g/kg, depending on the type of flax fibers and reduction method. By insertion of AgNPs, the scoured fibers were acquired reddish-yellow color with color strength of 8.7–10.5 related to the surface plasmon resonance AgNPs. The AgNPs-scoured flax fibers were exhibited by very good UV protection (30 < UPF < 40) and excellent antibacterial activity. The release of Ag from flax fibers was quite low (2.2–15.4 %) confirming that the functionalized fibers had good durability. In one pot step without bleaching, scoured flax fibers were gained concurrent/durable triple functions, which considerably valuable for the economical and environment impact in industrialization of flax.

Cervical intraepithelial neoplasia (CIN) is a precancerous lesion of cervical malignant tumors. CIN is closely related to persistent human papillomavirus (HPV) infection, sexual behavior, and number of childbirths. The effect of vaginal microbial metabolites (VMM) on CIN is unclear; hence, we studied the effects of VMM and high-risk HPV (HR-HPV) infection on CIN and the clinical effects of nano-silver after loop electrosurgical excision procedure (LEEP). We selected the patients who went to the obstetrics and gynecology department of our hospital from January 2019 to November 2020, and we conducted vaginal microbiology, HPV typing, and histopathological examination on 282 patients. Among them, six patients had cervical cancer, 136 patients with CIN were regarded as the CIN group, and 140 patients with normal pathological tissue were regarded as the normal group. The results showed that H2O2and HR-HPV infection were significantly correlated with the risk of CIN (P< 0.05). LEEP was performed on CIN patients, and the treatment with nano-silver gynecological antibacterial suppository was postoperatively compared with patients without special treatment. The results show that postoperative treatment with nano-silver can shorten the bleeding and exudation time of the wound and promote wound healing. It can simultaneously reduce wound infection and promote HPV to become negative, which can effectively reduce postoperative complications and recurrence.

Silver nanoparticles in this study were prepared using the method of laser ablation in liquids (PLAL) at two energies (540 and 700) mJ and the count of pulses were (100,200,300 and 400) pulse . The prepared samples were divided into three groups: the first group of the samples were kept as they are without any irradiation but the second and third group were irradiated by Co-60 source with two amount of doses (7.5 and 11) KGy respectively . A series of measurements and studies were done, and from the pictures of Transmitted Electron Microscope (TEM) , it was observed that the prepared nanoparticles at laser energy (540) mJ with pulses count (400) pulse were spherical but the prepared nanoparticles at laser (700) mJ with pulses cont (400) pulse were nano rods shape. The gamma irradiation effect was studied through its effect on the optical properties of the nanoparticles at different preparation conditions , represented by a change in the pulses and the energy of the laser used. The results showed that there was an increase the absorbance peaks when increasing the irradiated dose. The (TEM) image showed we get spherical nanoparticles in shape and nano composition. The average diameter of the prepared silver nanoparticles at (540) mJ laser energy in the range of (30-40) nm.

This research focused on isolation of Silver Nano Particles (AgNPs) using leaf filtrate of Ocimum sanctum and evaluation of their antibacterial action against Bacillus aureus, Staphylococcus aureus and Escherichia coli. It is known that plant extracts act as reducing agents, stabilizers and as capping agents. The O. sanctum plant was specifically selected due to its medicinal properties and abundant availability. The change in color of leaf extract was imminent when the silver nitrate was added to the basil leaf filtrates, indicating the formation of AgNPs. The UV-visible spectroscopy and SEM analysis confirmed the formation of AgNPs. Silver ions and nanoparticles are severely toxic to microorganisms; hence they are used predominantly as antimicrobial agents. The silver nanoparticles that were synthesized from O. sanctum leaf extract have exhibited antibacterial activity against Klebsiella, B. aureus, S. aureus and E. coli and the activity varied significantly with the different concentrations of silver nitrate used. The nano particles thus developed have been confirmed by UV along with SEM reports. AgNPs sizes varied from 53.3 to 121 nm. It has been observed that most of the plant extracts yielded silver nano particles of size less than 100 nm. However, the present experimental work yielded particle size of about 121 nm from O. sanctum leaf extract. Key words: Silver nano particles (AgNPs), Ocimum sanctum, antibacterial activity.

Convenience food has become an inseparable part of today’s hectic life and its quality, durability, and health level should be highlighted. Food packaging is the most popular way to prevent bacterial spoilage and nutrient loss. Meanwhile, emerging antibacterial packages have shown additional properties in increasing storage time. Here, the effect of using polyethylene packages containing silver nanoparticles with different concentrations (0.02 and 0.04%) on the durability, appearance, microbial, and organoleptic properties of Olivier salad was investigated. In this regard, Olivier salad was packaged in 3 sets of polymer packages containing 0, 0.02 and 0.04% silver nanoparticle. The samples were then under test for 2-, 12-, and 22-day periods where microscopic, microbial, and sensory analyses were conducted. Scanning electron microscope (SEM) was implemented in physical characterization and the silver ions migration from the packages to the sample was measured by atomic adsorption method (AA). In addition, texture, taste, and general acceptance of packaged samples were studied by a 9-point evaluation method and trained panelists and the color and appearance by Image J software. SEM images proved the presence and proper distribution of nanocrystalline structure in the packages. Microbial tests’ results showed that the overall counting of micro-organisms and mold increased with increasing storage time and decreased with increasing nanoparticle concentration in the packages. Also, coliform count decreased in all three packages (containing no, 0.02 and 0.04% silver nanoparticle) with time, and the concentration of nanoparticles in the nano-silver packages had no effect on coliform results. All sensory characteristics were better in samples with silver nanoparticle packages and AA results showed a direct relationship between ion migration and storage time and silver nanoparticle weight fraction. Finally proper curves were fitted over different experimental data and resultant equations were optimized in definite ranges (silver nanoparticle concentration = 0–1000 ppm, time = 0–15 days, total bacteria count = 17,500–14,500,000 cfu/g, Coliform = 0–3300 cfu/g, mold and yeast = 200–2,500,000 cfu/g, taste = 9-65, texture = 11–55, total acceptance = 12–65, color parameter L* = 68.886–95.132, Ag ion migration = 0–10). It was concluded that the antibacterial effect as well as perfect performance in keeping the properties fresh for around 14 days could be accomplished with a concentration of 404.93 ppm for silver nanoparticles.

Background. The present study evaluated the antimicrobial efficacy of composite resins containing nano-silver (NAg) particles used in fixed orthodontic retainers. Methods. Nano-composite resin samples with 1%, 2%, and 5% concentrations of NAg were prepared. The antimicrobial effectiveness of NAg was assessed against Streptococcus mutans, Streptococcus sanguis, and Lactobacillus acidophilus by the biofilm inhibition test (three-day-old biofilms), eluted components test (on days 3, 15, and 30), and disk-diffusion agar test after 48 hours. Measures of central tendency and index of dispersion were used to determine colony-forming units. Kruskal-Wallis test and Mann-Whitney U test were also used. Results. The biofilm inhibition test showed a significant decrease in the colonies of S. mutans (87.64%, 96.47%, and 99.76% decrease), S. sanguis (98.13%, 99.47%, and 99.93% decrease), and L. acidophilus (81.59%, 90.90%, and 99.61% decrease) at 1%, 2%, and 5% concentrations of Nag, respectively, compared to the control groups. The colony-forming unit (CFU)/mL of tested microorganisms continuously decreased with increased NAg concentration. In the eluted component test, no significant differences were noted in the 3rd, 15th, and 30th days between the different concentrations of Nag-containing composite resin disks and control samples. According to the disk-diffusion agar test, there was no growth inhibition zone for the composite resin disks containing 1% and 2% concentrations of Nag. However, the growth inhibition zone was seen with a 5% concentration, with a diameter of 9.5±0.71 mm for S. mutans, 8.5±0.71 mm for S. sanguis, and 8±1.41 for L. acidophilus. Conclusion. The incorporation of NAg into composite resins has antibacterial effects, possibly preventing dental caries around fixed orthodontic retainers.

As a kind of rare materials, nano-silver has broad application prospects in the fields of catalysis, medical treatment, new energy and so on. However, there are few reports on the systematic research of nano-silver in ceramic glazes. In this work, different color ceramic glazes were produced by tuning the nano-silver content and optimizing the firing process. The crystalline phase composition, micro-morphology and elemental distribution of fired glazes were analyzed and discussed in depth. The elemental composition and distribution of the samples were studied. The surface of the glazes with varying Ag contents fired under the reducing atmosphere exhibited blue-white. And the blue color is attributable to Rayleigh scattering that may arise because the phase-separation structures existed in glazes. Interestingly, the color of the ceramic glazes with varying Ag contents changed to golden-yellow when the ceramic glazes were fired under the air atmosphere. Golden-yellow color of the samples fired under the air atmosphere is mainly attributable to the silver nano-particles, though Ag+ may be existed in the glazes.

American foulbrood (AFB) and European foulbrood (EFB) are the two major bacterial diseases affecting honeybees, leading to a decrease in viability of the hive, decreasing honey production, and resulting in significant economic losses to beekeepers. Due to the inefficiency and/or low efficacy of some antibiotics, researches with nanotechnology represent, possibly, new therapeutic strategies. Nanostructure drugs have presented some advantagesover the conventional medicines, such as slow, gradual and controlled release, increased bioavailability, and reduced side-effects. In this study, different infected larvae were collected from two apiaries; the combs that had symptoms of American and European foulbrood were isolated. In vitro antimicrobial activity of camphor tree silver nano-particles against foulbrood diseases were characterized using UV-Vis spectrophotometry and scanning electron microscope (SEM) that proves the formation of silver nanoparticles with size range 160-660 nm. The antimicrobial activity of the silver nanoparticles was tested using agar diffusion assay and proved their ability to effectively cease the pathogenic bacterial growth in both AFB and EFB. DGGE-PCR technique has been applied for the identification of un-common bacterial infections honeybees depending on 16S rRNA amplification from their total extracted DNA and has been identified as Serratia marcescens (TES), deposited in GenBank with a new accession number (MT240613). The results were confirmed strain has been detected by DGGE-PCR analysis causing uniquely infected brood that was attacked by the American Foulbrood It could be concluded that greenly synthesized silver nanoparticles is projected to be used as effective treatment for honeybee bacterial diseases. These material need more investigations under field conditions and study the possibility of its residues in honeybee products such as honey, and beeswax.

In order to explain the interaction between collagen and nano-silver, gelatin solution was blended with nano-silver particles (AgNPs) with particle size 26 mm, and then the mixture was interacted under different time, pH and temperature. The changes in the process were measured by UV-Vis, fluorescence spectroscopy, dynamic light scattering and FT-IR. The results showed that the main type of reaction between gelatin and AgNPs was electrostatic interaction and the interaction was diffusive encounters. The particle size and distribution of nano-silver would not be affected by gelatin, however, there was dynamic fluorescence quenching of gelatin after nano-silver particle induced. The longer time and lower pH were beneficial for the interaction process while the interaction balanced after 60 min and pH 3.0 resulted in the most drastic interaction. Moreover, nano-silver would not impair gelatin structure during the interaction process. In short, the results in this work might be a foundation and reference for applying nano-silver in antibacterial leather producing.

Since the discovery of carbon nanotubes, carbon nanotubes have quickly become a research hotspot for scholars worldwide due to their unique special properties such as mechanical, electronic, and ch...

Possible high biodeterioration of the microorganisms due to their metabolic pathway and activities on stone materials causes solemn problems in cultural heritage. Different kinds of laboratory-scale methods have been used for the reduction of microbial growth, that is, chemical, mechanical, and physical, which are cost-effective and not ecofriendly. In the current study, an ecofriendly approach utilizing silver nanoparticles were synthesized using sheep blood serum. Transmission electron microscopy results have confirmed the spherical and well dispersed silver nanoparticles with an average size of 32.49 nm, while energy dispersive X-ray has shown the abundance of silver nanoparticles. The efficiency against bacterial species was verified through laboratory-scale testing. The strong antibacterial activity was confirmed when B-AgNPs was tested against different bacterial species isolated from the Beishiku Cave Temple. The largest zone of inhibition was measured 26.48 ± 0.14 mm against Sphingomonas sp. while the smallest zone of inhibition measured was 9.70 ± 0.27 mm against Massilia sp. Moreover, these ecofriendly B-AgNPs were tested for daily based dose in different concentrations (0.03, 0.06, and 0.09 mg/L) against common carp fish for a long exposure (20 days) and 6.5% fatality was found. The highest lethal concentration (LC50 ) for fish (0.61 ± 0.09 mg/L). No doubt, the laboratory scale applications have revealed the best results with minute toxicity in fish. Therefore, sheep serum should be continued to synthesize silver nanoparticles on a large scale. A strict monitoring system should be developed for the synthesis and application of AgNPs.

92 cases of second degree burn wounds treated in our hospital from January 2019 to December 2019 were selected as the research objects, and the clinical effect of eCASH concept treatment combined with nano silver dressing on the second degree burn wounds was studied. The patients were randomly divided into control group (n = 46) and observation group (n = 46). The control group was treated with conventional treatment combined with eCASH concept nursing, and the observation group was treated with eCASH concept combined with nano silver dressing. We found that the effective rate of the observation group was 95.65% higher than that of the control group (76.09%); the wound healing time of the observation group was significantly lower than that of the control group; the average VAS pain score of the observation group during wound treatment was significantly lower than that of the control group The total positive rate of bacterial detection in the observation group was 8.70%, which was lower than 28.26% in the control group; the incidence of complications in the observation group was 2.17% lower than that in the control group (17.39%); the differences were statistically significant (all P < 0.05). These results indicate that eCASH concept combined with nano silver dressing in the treatment of second degree burn wounds has a significant effect, which can accelerate the recovery, reduce the pain, and effectively reduce the total positive rate of bacterial detection and the incidence of complications.

The antimicrobial activity of biosynthesized silver nanoparticles (AgNPs) from the leaves of four medicinal plants,Caricapapaya (CP), Moringa oleifera (MO), Mangifera indica (MI) and Garcinia kola (GK)were assessed against selected gram positive and gram-negative bacteria. Method of synthesis of nanoparticles utilized was the eco-friendly Bio-based method using plant leaves extract as reducing and stabilizing agents. Two different ratios for each plant extract and silver nitrate (1:1 and 1:2) respectively were used. Particle characterization was carried out using visual inspection and UV-Vis spectrophotometry. Antimicrobial activity was assessed using agar diffusion method. Visual inspection revealed gradual color change from golden yellow to dark brown, confirming nanoparticles formation. The surface plasmon resonance peak was between 416 and 438 nm for the silver nanoparticles. The minimum inhibitory concentration ranged from 3.125 - 12.5µg/ml. In conclusion, all four biogenic silver nanoparticles have reasonable antimicrobial activity with ratio 1:2 being more potent.&nbsp

Objectives To determine whether the incorporation of N-acetylcysteine (NAC) improves the antibacterial ability and biocompatibility of nano silver (NAg)–containing orthodontic cement. Materials and Methods NAg was synthesized using a sodium citrate reduction method. NAg particles were characterized using transmission electron microscopy and ultraviolet-visible absorption spectra. NAg and NAC were incorporated into a resin-modified glass ionomer cement. Enamel shear bond strength (SBS), antibacterial capability, and cytotoxicity were evaluated. Results Incorporating 0.15% NAg and 20% NAC had no adverse effect on the SBS of orthodontic cement (P > .1). Adding NAC into NAg-containing cement greatly reduced the biofilm metabolic activity and lactic acid production (P < .05) and lowered the colony unit–forming counts by approximately 1 log (P < .05). The cell viability against NAg-containing cement was improved by NAC (P < .05). Conclusions The incorporation of NAC into NAg-containing cement achieved stronger antibacterial capability and better biocompatibility, without compromising the enamel SBS. The combined use of NAC and NAg is promising to combat caries in orthodontic practice.

The hydrogels based on cross-linked dextran-graft-polyacrylamide (D-g-PAA) and polyacrylamide (PAA) with different densities of chemical cross-links were synthesized by radical polymerization. They were used as nanoreactors for the photochemical synthesis of silver nanoparticles (AgNPs). The polymer hydrogels and nanocomposites with loaded AgNPs were characterized by SEM, FTIR- and UV–Vis spectroscopy. Swelling studies demonstrated differences in the internal structure of the cross-linked D-g-PAA and PAA samples. The morphology of the hydrogels affects the properties of the obtained nanocomposites. The microbiological tests have shown that the D-g-PAA-based hydrogels loaded with AgNPs are more active against Staphylococcus aureus than their PAA-based counterparts and can be an efficient alternative to antibiotic-containing coverings and dressings.

In this study, ultra-small nano-Ag particles with an average diameter of 4.76 nm and excellent stability have been synthesized on a large scale to meet low-temperature, low-pressure, and lead-free packaging requirements for modern high-power electronic applications. Citrate coated nano-Ag particles’ agglomerations have been used in the form of a nano-Ag paste to solder by a robust Cu to Cu direct bonding. The bonding strength of the formed Cu-Cu joint reaches 28.2 MPa when sintered at 260 °C for 30 min and 1 MPa. The bonding mechanism of such a direct Cu-Cu bonding by using nano-Ag paste has been facilitated by the assistance of an in-situ sintering of nano-Ag particles. The analysis of the bonding has been performed using a transmission electron microscopy (TEM) and a focused ion beam (FIB). The results show that the bonding mechanism can be interpreted by two parts: (1) self-sintering process of nano-Ag paste, and (2) interfacial bonding between sintered nano-Ag paste and Cu substrate.

The goal of endodontic treatment is the debridement and removal of the microbial ecosystem associated with the disease process. The need for root canal disinfectants increases especially in those cases where infection is resistant to the regular treatment and the outcome of endodontic therapy is often compromised. Therefore, it is of interest to document the known effectiveness of silver nanoparticle based root canal disinfectants with other root canal disinfectants on microbial load reduction during root canal disinfection. Known data shows that the overall risk of bias for the selected studies was moderate. Silver nanoparticle based root canal disinfectants showed superior reduction of microbial counts in majority of the studies. This data is limited to vitro studies with no clinical information to validate the use of antimicrobial properties of silver nanoparticles used as root canal disinfectant.

The progress of nanoparticles production by eco-friendly route, with desirable chemical and physical characteristics, and their application in helpful fields is still under investigation. Therefore, this study aimed at biosynthesis, characterization, and biomedical applications of silver nanoparticles (AgNPs) using yeasts metabolite. The yeast strains, Pichia kudriavzeviiHA-NY2 and Saccharomyces uvarumHA-NY3, were used for extracellular biosynthesis of AgNPsK and AgNPsU, respectively. AgNPs were characterized by UV–visible spectrophotometry, transmission electron microscopy (TEM), Fourier Transformed Infrared (FTIR) spectrum and dynamic light scatter (DLS). TEM image showed well dispersed round and cubic regular particles with size ranges of 12.4 ± 6.02 nm for AgNPsU and 20.655 ± 9.48 nm for AgNPsK. According to DLS analysis, the mean size diameters of AgNPsU and AgNPsK were 20.3–21.5 and 29.6–30.14 nm, respectively. AgNPs showed highly significant inhibitory activity against gram-positive bacteria (Bacillus subtilis ATCC6633 and Staphylococcus aureus ATCC29213), gram-negative bacteria (Pseudomonas aeruginosa ATCC27953), Candida tropicalis ATCC750, and Fusarium oxysporium NRC21. The anti-inflammatory activity of AgNPs revealed that paw edema was inhibited by the oral administration of the two biosynthesized silver-nanoparticles. In addition, they showed carrageenan activity nearest to indomethacin. All fabricated AgNPs showed a significant analgesic effect after one hour of administration, which was comparable to aspirin. Further, both AgNPsK and AgNPsU demonstrated a significant anticancer activity against HCT-116 (Colon cell line) with IC50 values 0.29, 0.24 µg ml−1, respectively, and PC3 (Prostate cell line) with IC50 values 0.57, 0.50 µg ml−1, respectively. No ulcerogenic effects of AgNPs were detected on the rats’ stomach and it was safe on the gastric profile.

Owing to develop the utilization of biowaste materials and minimize the usage of plastic materials, Orange peel Powder (OPP) biowaste is chosen as filler material along with Polyvinyl Alcohol (PVA) as a matrix to form biocomposite films. To stretch its applications to antibacterial applications the metal nanoparticles were incorporated by the in-situ generation of Ag by reducing the various concentration of the aqueous solution of AgNO3 to fabricate novel PVA/OPP/(1 mM to 5 mM)AgNPs hybrid biocomposite films. The fabricated biofilms were undergone the antibacterial test, mechanical test, and characterized by FESEM, FTIR, XRD & thermal analysis. The FESEM images clarify the homogenous distribution of filler materials in the PVA matrix and binding between the filler materials & matrices. FT-IR spectrum illustrates, there is no functional group change in the films by the inclusion of AgNPs as compare to the PVA/OPP films and indicates the strong adhesion and well dispersion of filler materials. XRD patterns confirm the presence of Ag and accentuated the crystallite size of generated AgNPs in the films as 23.44 nm, 25.59 nm, 26.25 nm, 28.17 nm, and 28.42 nm. Thermal analysis of the films shows improved thermal stability as well as glass transition temperature of the composite films included with AgNPs, also the considerable increase in the tensile strength and tensile modulus of the PVA/OPP/AgNPs films as compared to the neat PVA, PVA/OPP films. As compare to neat PVA and PVA/OPP films, with the increase of concentration of AgNO3 source solution antibacterial activity of the PVA/OPP/AgNPs films increases against gram-negative and gram-positive bacteria. With the above-improved results by the inclusion of Ag nanoparticles, this hybrid biocomposite films can be utilized in food processing industries

This work aims to synthesis silver nanoparticles using the extract of resurrection plant as a reducing agent. The resulting product of silver nanoparticles was characterized using XRD and TEM and the results show that there is a pure silver nanoparticles was produced with sphere-like nano silver of 30–50 nm. Furthermore, the as-prepared nanosilver was used as potential anti-bacterial against two Gram positive bacteria; s. aureus and s. epidermidis. The results prove that the as-prepared silver nanosphere is able to inhibit the bacteria growth with maximum inhibition zone diameter of 15 mm (s. aureus) and 20 mm (s. epidermidis) using 160 µg/ml concentration from Ag nanospheres.

To meet the high-precision needs of conductive ink in the field of microelectronic circuit printing, nano silver-coated graphene oxide (GO) composites were prepared as the conductive functional unit of the composites. The results show that compatibility of the GO grafted with ethylene glycol diglycidyl ether is better in the organic matrix than in the inorganic solvents. The nano silver particles attached to the surface of the grafted GO are evenly distributed and uniform in size. Moreover, the conductivity of grafted GO coated with silver particle composites is effectively improved. The composite conductivity is higher than 108 S/m, which is close to the electrical conductivity of silver.