Addition Of AgNO3 Research Articles

Highly selective oxidation of 5-HMF to HMFCA via a facile Pt-Ag co-catalytic strategy

5-Hydroxymethyl-2-furancarboxylic acid (HMFCA) is an important feedstock in chemical and pharmaceutical industries. Its production through aerobic conversion of 5-hydroxymethylfurfural (5-HMF) has promising prospects but is challenged by the over-oxidation. In this work, we develop a refined Pt-Ag co-catalytic strategy to tailor the selectivity of 5-HMF’s aerobic oxidation. By simple in situ addition of AgNO3 to the thermal catalytic system of Pt nanoparticles, the main products of 5-HMF oxidation could be shifted from 2,5-furandicarboxylic acid (FDCA) to HMFCA with an ultrahigh selectivity of over 99 %. Density functional theory calculations demonstrate that such strategy could alter the HMFCA adsorption sites from Pt to Ag sites and prevent the oxidation of hydroxymethyl group. In addition, this strategy can be extended to other Ag species, such as AgCl, Ag2O and AgO. This work provides insights into the Pt-Ag synergistic catalysis and opens up a simple avenue to control the product selectivity for biomass refinement.

Influence of Silver Nanoparticles on the Metabolites of Two Transgenic Soybean Varieties: An NMR-Based Metabolomics Approach.

This study investigated the effect of AgNPs and AgNO3, at concentrations equivalent, on the production of primary and secondary metabolites on transgenic soybean plants through an NMR-based metabolomics. The plants were cultivated in a germination chamber following three different treatments: T0 (addition of water), T1 (addition of AgNPs), and T2 (addition of AgNO3). Physiological characteristics, anatomical analyses through microscopic structures, and metabolic profile studies were carried out to establish the effect of abiotic stress on these parameters in soybean plants. Analysis of the 1H NMR spectra revealed the presence of amino acids, organic acids, sugars, and polyphenols. The metabolic profiles of plants with AgNP and AgNO3 were qualitatively similar to the metabolic profile of the control group, suggesting that the application of silver does not affect secondary metabolites. From the PCA, it was possible to differentiate the three treatments applied, mainly based on the content of fatty acids, pinitol, choline, and betaine.

Synthesis of Smart Packaging from Cellulose Acetate with The Addition of AgNO3 as An Antibacterial Substance

Synthesis of smart packaging from cellulose acetate with the addition of AgNO3 as an antibacterial substance has been investigated. The purpose of this study is to fabricate smart packaging from cellulose acetate with the addition of AgNO3 as an antibacterial substance. The method used was solution casting. In addition, this study was also characterizing the smart packaging, they included tensile strength and elongation percent test, antibacterial test, morphology analysis using SEM, and biodegradability test. The plastics obtained were clearly yellow, not easily damaged, a little thick, and the smooth surface and slightly bubbly. The largest tensile strength of plastic was 0.0661 MPa, it found in sample No. 2, while the smallest tensile strength was 0.027 MPa, it found in sample No. 1. The greatest elongation value at break was 5% found in sample No. 4, while the smallest elongation value at break was 3.5% in sample No. 3. The result of antibacterial test reported that the freshest mangoes were shown by samples No. 1 and No. 2; while the fast-rotting mangoes were shown in the sample No. 3 and No. 4. The results of the SEM test showed the presence of nano-sized particles that spreaded in the plastic body. The greatest degradability degree were sample No. 4 about 0.0009 g/day with the percentage of mass loss about 17.38%. Futhermore, cellulose acetate can be used as a basic material for making plastics. The addition of AgNO3 in plastic synthesis can help to delay the process of fruit spoilage caused by bacteria.

One-step preparation of silver nanoparticle containing polymer nanocomposites via stereolithography technique

As a technique that uses ultraviolet light to cure photo-polymers layer by layer with high spatial resolution and surface quality, stereolithography (SLA) allows for precise process control and optimization for various UV-curable polymers and their nanocomposites with various nanoparticles. In this study, UV-curable polymer nanocomposites were prepared with the addition of different contents of silver nitrate via SLA technique for use in antibacterial applications. In-situ synthesis of AgNPs was achieved during the SLA process without any additional treatments. The effect of AgNO3 addition on the curing of the resin and the mechanical properties of the nanocomposite specimens were investigated. To understand the fracture mechanism of the nanocomposite samples, the fractured surfaces of the samples were evaluated by SEM, and the AgNO3 content of the nanocomposite was evaluated by EDX. The nanocomposites containing 0.3 wt. % AgNO3 exhibited improved mechanical properties. Further increasing the AgNO3 content to 3 wt. % led to deterioration in the physical and mechanical properties of the polymer nanocomposites.

Absorption and Biotransformation of Selenomethionine and Selenomethionine-Oxide by Wheat Seedlings (Triticum aestivum L.)

An in-depth understanding of Se uptake and metabolism in plants is necessary for developing Se biofortification strategies. Thus, hydroponic experiments were conducted to investigate the associated processes and mechanisms of organic Se (selenomethionine (SeMet) and selenomethionine-oxide (SeOMet)) uptake, translocation, transformation and their interaction in wheat, in comparison to inorganic Se. The results showed that Se uptake by the roots and the root-to-shoot translocation factor under the SeMet treatment were higher than those under the selenite, selenate and SeOMet treatments. The uptake and translocation of SeMet were higher than those of SeOMet within 72 h, although the differences gradually narrowed with time. The uptake of SeMet and SeOMet was also sensitive to the aquaporin inhibitor: AgNO3 addition resulted in 99.5% and 99.9% inhibitions of Se in the root in the SeMet and SeOMet treatments, respectively. Once absorbed by the root, they rapidly assimilated to other Se forms, and SeMet and Se-methyl-selenocysteine (MeSeCys) were the dominant species in SeMet- and SeOMet-treated plants, while notably, an unidentified Se form was also found in the root and xylem sap under the SeMet treatment. In addition, within 16 h, SeOMet inhibited the uptake and translocation of SeMet, while the inhibition was weakened with longer treatment time. Taken together, the present study provides new insights for the uptake and transformation processes of organic Se within plants.

Sustainable preparation of AuAg alloy@AgBr Janus nanoparticles via dissipative self-assembly for photocatalysis.

We report a facile synthesis of cetyltrimethylammonium bromide (CTAB) templated AuAg alloy@AgBr Janus-nanoparticles (JNPs) using a non-conventional top-down approach with precise control over symmetry breaking. The addition of AgNO3 to a micellar solution of CTAB results in micelle-stabilized AgBr colloids having excess Ag+ at the interstitial sites of AgBr. AgBr colloids undergo weak self-assembly supported by inter-micellar interactions. The interfacial disturbance of self-assembled colloids via electrostatic adsorption of AuCl4- or Au(OH)4- at the micelle-AgBr interface downsizes the colloids. This is followed by the growth of the AuAg phase onto AgBr resulting in AuAg alloy@AgBr JNPs via different reduction pathways (photoreduction or chemical reduction) in the presence of ascorbic acid. The prepared JNPs act as efficient visible light photocatalysts for the degradation of aqueous rhodamine B. Interestingly, the trapping of holes favors the photocatalytic efficiency. Furthermore, the JNPs have shown proficiency in inhibiting the growth of both Gram-positive and Gram-negative bacteria as compared to the commercial antibiotic kanamycin, with a very low MIC value of ∼35 μg ml-1. In this way, a new single-pot strategy for the controlled preparation of photo-catalytically active and antimicrobial AuAg alloy@AgBr JNPs governed by dissipative self-assembly is reported for the first time.

Impact of AgNO3 Addition on Luminescence of Er3+ Ion Doped Zinc–Aluminum–Sodium–Fluorophosphate (ZANP) Glasses

Impact of AgNO3 Addition on Luminescence of Er3+ Ion Doped Zinc–Aluminum–Sodium–Fluorophosphate (ZANP) Glasses

Synthesis, Characterization, and Antibacterial Activity Test of Geothermal Silica/AgNO3 Thin Film

Geothermal silica waste offers convenient, economical, and environmentally friendly material with high hydrophobicity to produce thin films. Silica-thin films from geothermal waste using the sol-gel method, though, no addition of AgNO3 was conducted for antibacterial functions. This study aims to produce silica-thin films from geothermal waste with the addition of AgNO3 and analyze the antibacterial activity. The procedures carried out in this research were (i) an acid leaching process using HNO3; (ii) the production of silica thin film with and without the addition of AgNO3; (iii) thin film characterization including a water contact angle measurement (WCA), XRF, FTIR, XRD and SEM-EDX on silica thin film samples with and without the addition of AgNO3; and (iv) antibacterial activity test. The results show the optimum HNO3 concentration for the acid leaching process was 20%, yielding 99.08% SiO2 by mass. The WCA of the silica thin film in the presence and absence of AgNO3 reached a value of ±160°, indicating the addition of AgNO3 did not decrease the contact angle of the silica thin film. This research employed smart deconvolution of IR Spectra using Fityk software which reveals a higher area ratio for Si-O-Si relative to Si-OH. Furthermore, it was observed that the silica thin films exhibited an amorphous morphology, both without and with the addition of AgNO3, with Ag discovered to be dispersed on the thin film. However, despite the presence of Ag, both TF20 and TF20+Ag samples were found to be ineffective in inhibiting bacterial growth, as evidenced by bacteria-free zones on the samples.

Mycosynthesis of silver nanoparticles using psychrotrophic strains of Tulasnella albida Bourdot & Galzin from the South Orkney Islands (Antarctica)

This study is the first report on mycosynthesis of silver nanoparticles (NPs) using psychrotrophic Antarctic filamentous fungi, and the first report regarding Tulasnella (Basidiomycota). In this work, the ability to synthesize silver NPs from cell free filtrates of strains of Tulasnella albida isolated from Antarctica was assessed. All fungal filtrates were capable of synthesizing silver NPs with the addition of AgNO3. UV–vis spectroscopy, TEM and SEM microscopy analyses were performed to characterize the synthesized NPs. ATR-FTIR and Micro Raman spectroscopy analyses were conducted to find functional groups responsible for the reduction of AgNO3 and to detect the presence of silver oxide on the AgNPs. Theoretical calculations of optical absorption based on core-shell Ag–Ag2O were used to characterize the experimental absorption spectra of silver NPs colloids. Spherically shaped silver NPs, typically 2–3nm in diameter, were obtained. The largest ones showed a capping shell around them, which could be associated with the formation of small silver NPs. Functional groups corresponding to amides and alcohols were detected, confirming the presence of proteins as possible intermediates in the synthesis of AgNPs. On the other hand, the Micro Raman analysis confirms the presence of silver oxide on the surface of the AgNPs. This work presents a simple procedure for the synthesis of silver NPs using a psychrotrophic organism that could be interesting for the industry.

Metabolic response induced by abiotic elicitors in Anacardium othonianum seedlings

Applying elicitors in plants growing under natural conditions change the metabolic content of volatile compounds extracted from their tissues. Here, we have investigated how abiotic elicitors influence the volatile composition of the ethyl acetate extract of Anacardium othonianum seedlings propagated in vitro and ex-vitro cultures. Abiotic factors such as salicylic acid, silver nitrate, light quality, and cultivation mode affected the composition of volatile compounds in ethyl acetate extract of A. othonianum leaves seedlings. GC/MS analysis demonstrated that α-tocopherol was the main metabolite in cultures added with chemical elicitors, reaching 22.48 ± 4.06% in the case of 30 µM salicylic acid. Higher concentrations of salicylic acid decreased the amount of α-tocopherol. The addition of AgNO3 had a linear effect on α-tocopherol. Thus, the production of this metabolite indicates that salicylic acid and AgNO3 elicitors positively affect α-tocopherol production at specific concentrations helping to understand how plant culture can be better manipulated.

Green synthesized silver nanoparticles for iron and manganese ion removal from aqueous solutions

Microalgae and Cyanobacteria extracts can be used for the synthesis of spherical silver nanoparticles by the reduction of AgNO3 under air atmosphere at room temperature. Here, we synthesized AgNPs using extracts of one cyanobacterium (Synechococcus elongatus) and two microalgae (Stigeoclonium sp. and Cosmarium punctulatum). The nature of the AgNPs was characterized by TEM, HR-TEM, EDS, and UV–Vis. Considering the large quantity of functional groups in the ligands of AgNPs, we suppose they could retain ion metals, which would be useful for water decontamination. Thus, their capacity to adsorb iron and manganese at concentrations of 1.0, 5.0, and 10.0 mg L−1 in aqueous solutions was evaluated. All experiments were performed in triplicate of microorganism extract with no addition of AgNO3 (control) and AgNP colloid (treatment) at room temperature. The ICP analyses showed that the treatments containing nanoparticles were commonly more efficient at removing Fe3+ and Mn2+ ions than the corresponding controls. Interestingly, the smaller nanoparticles (synthesized by Synechococcus elongatus) were the most effective at removing Fe3+ and Mn2+ ions, probably due to their higher surface area:volume ratio. The green synthesized AgNPs proved to be an interesting system for the manufacture of biofilters that could be used to capture contaminant metals in water.

Fabrication of Unidirectional Water Permeable PS/PET Composite Nanofibers Modified with Silver Nanoparticles via Electrospinning

In this study, the composite nanofiber membranes (AgNPs-PS/PET) composed of hydrophobic polystyrene (PS) embedded with different additions of silver nanoparticles (AgNPs) and hydrophilic hydrolyzed polyethylene terephthalate (PET) were prepared via electrospinning technology to achieve the function of unidirectional water penetration. The addition of AgNO3 was at 0 wt%, 0.5 wt%, 1.0 wt% and 1.5 wt% as the variables. The surface morphology and structure of AgNPs-PS/PET composite nanofibers were characterized by scanning electron microscopy (SEM), x-ray energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The SEM image showed that the fibers of the composite materials were continuous and uniform as a result of electrospinning. The presence and content of Ag nanoparticles dispersed in the nanofibers were investigated using EDS and TEM. The contact angle (CA) was tested to illustrate the wettability of the composite nanofiber membranes using a static contact angle measuring instrument and the process of unidirectional water penetration was recorded. Meanwhile, the mechanism of unidirectional water penetration was analyzed. Moreover, the electrospinning solution's viscosity and conductivity were also investigated. Eventually, the optimal addition of AgNO3 (1.0 wt%) was confirmed and the prepared AgNPs-PS/PET composite nanofiber membranes were able to achieve the function of unidirectional water penetration. These membranes have the potential to be applied in smart textiles, unidirectional water collection and wound dressing.

The anti SARS-CoV-2 activity of nanofibrous filter materials activated with metal clusters.

Nanofibrous filter materials were prepared by electrospinning a solution of 28wt% poly(vinylidene fluoride) in N,N-dimethylacetamide with and without the addition of 2wt% AgNO3, Cu(NO3)2·2.5H2O or ZnCl2. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy, inductively coupled plasma mass spectroscopy, thermogravimetric analysis, contact angle measurement, nitrogen sorption, and mercury intrusion porosimetry methods were used for the characterization of physical structure as well as the chemical composition of the electrospun materials. Particle filtration efficiency and antiviral activity against the SARS-CoV-2 alpha variant were tested in order to estimate the suitability of the prepared electrospun filter materials for application as indoor air filtration systems with virucidal properties. All filter materials prepared with salts demonstrated very high particle filtration efficiency (≥98.0%). The best antiviral activity was demonstrated by a material containing Cu(NO3)2·2.5H2O in the spinning solution, which displayed the decrease in the number of infectious virions by three orders of magnitude after a contact time of 12h. Materials with the addition of AgNO3 and ZnCl2 decreased the number of infectious virions after the same contact time by only ∼8 and ∼11 times, respectively.

Shape trimming and LSPR tuning of colloidal gold nanostars

Herein, we envisioned the post-synthetic shape tailoring/modification of Au nanostars (synthesized by complexation of Polyvinyl pyrrolidone (PVP) in Dimethyl formamide (DMF) under ambient conditions) by simply utilizing NaBr and Br2 for breaking the coordination bonds between PVP and metal, thereby preferentially etching specific crystal facets from Au nanostar spikes and redeposit them at the core, essentially leading to quasi-spherical dimensions with increasing time. Such synergistic tuning was modulated carefully in stabilizing/arresting the necessary intermediate morphologies by addition of AgNO3 at any point of time, allowing us to exploit the wide range of plasmonic applications in a refined manner.

Antibacterial Activity of AgNO3 Incorporated Polyacrylonitrile/Polyvinylidene Fluoride (PAN/PVDF) Electrospun Nanofibrous Membranes and Their Air Permeability Properties

Polyacrylonitrile (PAN)/polyvinylidene fluoride (PVDF) nanofibers incorporated with AgNO3 in various concentrations were produced as membranes and investigated for their antibacterial properties and air permeability. To characterize the AgNO3 incorporated PAN/PVDF nanofibers Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier-Transform Infrared (FT-IR) Spectroscopy, the Brunauer–Emmett–Teller (BET) method and air permeability analyses were carried out. Based on the SEM results, the prepared nanofibers had a smooth and beadless surface. For 20 wt% PVDF concentration, AgNO3 addition up to 20 wt% did not disrupt the fiber structure. The antibacterial activity of the AgNO3 incorporated PAN/PVDF nanofibrous membranes were investigated against bacterial strains of E. coli and S. aureus. For each AgNO3 concentration from 5 wt% to 20 wt%, the PAN/PVDF nanofibrous membranes showed antibacterial activity in correspondence with the measured inhibition zones. However, the 10 wt% AgNO3 concentration was found to be the optimum concentration providing desirable nanofiber morphology and antibacterial properties. Air permeability findings of the nanofibrous membranes did not show a significant difference for the tested AgNO3 concentrations. In summary, the results indicated that AgNO3 incorporated PAN/PVDF nanofibrous membranes are appropriate for use as air filtration materials.

Effects of AgNO3 in combination with some plant growth regulators on micropropagation of strawberry (Fragaria ananassa Duch)

Strawberry (Fragaria ananassa Duch), belong to Rosaceae family, is widely appreciated, mainly for its fruit characteristic aroma, bright red color, juicy texture, It is traditionally asexually propagated by rooted runners. To improve the strawberry varieties this method was not suitable due to incidence of many serious diseases infection resulting in the gradual degeneration of cultivars performance, so micropropagated strawberry plant has been introduced to prevent most of the plant and soil transmissible diseases. Micropropagated strawberry has several advantages, such as its ability to multiply virus free stock rapidly and, the improved capacity of these plants to produce runners for planting in the field. In this study, it was aimed to examine the interaction of BA, IBA and AgNO3 combinations at different micropropagation stages. Results showed the addition of AgNO3 to MS medium led to increase shoot number, shoot length, fresh and dry weight at multiplication shoots stage, shoots rooting % and root number at rooting stage. Survival plants %, plant height, leaves number and dry weight at acclimatization stage.

Studies on Extraction of Chitosan from Trichoderma Viridae and Effect of Chitosan Based Edible Coating on Cucumber

Abstract: The Biopolymer chitosan, formed from chitin, is one of the most widespread renewable natural materials on the earth. Chitin is a major component of the cell wall of fungi. In this research extraction of chitosan from the fungi Trichoderma viridae is done by simple deproteinization, Filtration and deacetylation. Total phenol content was measured using Gallic acid as standard. H2O2 scavenging activity of the chitosan was calculated. Furthur antibacterial activity was evaluated against the gram positive bacteria S.aureus and the gram negative bacteria E.coli. Edible coating, for cucumber to extend shelf life, is made from the chitosan using polyethylene glycol and glycerol. Nanocomposite based edible coating solution is synthesised by the addition of AgNO3, for further enhancement of antimicrobial activity. Edible coating to cucumber is done and incubated at room temperature and observed for 7 days. Non-coated samples and chemical coated samples were also maintained. The microbial load was measured by turbidity method on the 2nd and 6th day of coating. Nutrient analysis including Carbohydrate estimation, Protein estimation, Moisture loss estimation was also carried out. Keywords: Trichoderma viridae, Chitosan, Edible coating, Cucumber, Shelf life analysis

Evaluation of the Radiation-Protective Properties of Bi (Pb)-Sr-Ca-Cu-O Ceramic Prepared at Different Temperatures with Silver Inclusion.

The influences of the sintering process and AgNO3 addition on the phase formation and radiation shielding characteristics of Bi1.6Pb0.4Sr2Ca2Cu3O10 were studied. Three ceramics (code: C0, C1, and C2) were prepared as follows: C0 was obtained after calcination and only one sintering step, C1 was obtained after calcination and two sintering cycles, and C2 was prepared after the addition of AgNO3 at the beginning of the final sintering stage. C2 displayed the maximum volume fraction of the Bi-2223 phase (76.4 vol%), the greatest crystallite size, and high density. The linear mass attenuation coefficient (µ) has been simulated using the Monte Carlo simulation. The µ values are high at 15 keV (257.2 cm−1 for C0, 417.57 cm−1 for C1, and 421.16 cm−1 for C2), and these values dropped and became 72.58, 117.83 and 133.19 cm−1 at 30 keV. The µ value for the ceramics after sintering is much higher than the ceramic before sintering. In addition, the µ value for C2 is higher than that of C1, suggesting that the AgNO3 improves the radiation attenuation performance for the fabricated ceramics. It was demonstrated that the sintering and AgNO3 addition have a considerable influence on the ceramic thickness required to attenuate the radiation.

Development of Flexible Biceps Tremors Sensing Chip of PVDF Fibers with Nano-Silver Particles by Near-Field Electrospinning.

Polyvinylidene fluoride (PVDF) and AgNO3/PVDF composite piezoelectric fibers were prepared using near-field electrospinning technology. The prepared fibers are attached to the electrode sheet and encapsulated with polydimethylsiloxane to create an energy acquisition device and further fabricated into a dynamic sensing element. The addition of AgNO3 significantly increased the conductivity of the solution from 40.33 μS/cm to 883.59 μS/cm, which in turn made the fiber drawing condition smoother with the increase of high voltage electric field and reduced the fiber wire diameter size from 0.37 μm to 0.23 μm. The tapping test shows that the voltage signal can reach ~0.9 V at a frequency of 7 Hz, and the energy conversion efficiency is twice that of the PVDF output voltage. The addition of AgNO3 effectively enhances the molecular bonding ability, which effectively increases the piezoelectric constants of PVDF piezoelectric fibers. When the human body is exercised for a long period of time and the body is overloaded, the biceps muscle is found to produce 8 to 16 tremors/second through five arm flexion movements. The voltage output of the flexible dynamic soft sensor is between 0.7–0.9 V and shows an orderly alternating current waveform of voltage signals. The sensor can be used to detect muscle tremors after high-intensity training and to obtain advance information about changes in the symptoms of fasciculation, allowing for more accurate diagnosis and treatment.

Bacillus licheniformis (MN900686) Mediated Synthesis, Characterization and Antimicrobial Potential of Silver Nanoparticles.

The use of bacteria in the synthesis of silver nanoparticles (AgNPs) emerges as an ecofriendly and exciting approach. In the present study, we reported the biosynthesis of AgNPs by using culture supernatant of the bacteria Bacillus licheniformis (MN900686). The biogenically synthesized AgNPs were confirmed by the change in the color of the culture filtrate from yellow to brown after the addition of AgNO3. Further characterization performed by means of UV vis-spectroscopy showed absorption peak at 414 nm which confirmed the formation of AgNPs. Fourier Transfer infrared (FTIR) confirmed the involvement of biological molecules in the formation of nanoparticles (NPs). The SEM revealed that the NPs have approximately 38 nm size. The agar well diffusion assay was used to determine antibacterial activity while tube dilution method was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The human pathogenic bacterial strains i.e., P. aeruginosa (MN900691) and B. subtilis (MN900684), were used as test strains. The anti-bacterial assay against test strains revealed that these NPs showed concentration dependent increased zone of inhibition (ZOI). The maximum ZOI at 25 µL of AgNPs was 20 mm against B. subtilis after 24 hours of incubation. One-way ANOVA test showed significant ZOI (p ≤ 0.05) against B. subtilis. The MIC was ranged from 4.3-6.6 μg/mL while MBC ranged from 8.3 to 6.6 μg/mL. Overall, this study suggested that the biogenically synthesized NPs are an effective alternative source of antimicrobials against pathogenic bacteria.