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The increase in simultaneous exposure to magnetic fields and other hazardous compounds released from industrial applications poses multiple stress conditions on the ecosystems and public human health. In this work, we investigated the effects of co-exposure to a static magnetic field (SMF) and silver ions (AgNO 3 ) on biochemical parameters and antioxidant enzyme activities in the yeast Saccharomyces cerevisiae. Sub-chronic exposure to AgNO 3 (0.5 mM) for 9 h resulted in a significant decrease in antioxidant enzyme activity, including glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione transferase (GST). The total glutathione (GSH) level increased in yeast cells exposed to Ag. Additionally, a notable elevation in malondialdehyde (MDA) levels and protein carbonyl content was observed in both the AgNP and AgNO 3 groups compared to the control group. Interestingly, the SMF alleviated the oxidative stress induced by silver nitrate, normalizing antioxidant enzyme activities by reducing cellular ROS formation, MDA levels, and protein carbonylation (PCO) concentrations., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Nanoparticle synthesis under environmentally friendly conditions has been conducted utilizing natural resources in order to reduce the reliance on hazardous chemicals. For example, the utilization of microbial synthesis has enabled the production of nanoparticles that exhibit biocompatibility, stability, and safety. Microorganisms facilitate the growth of crystals while preventing aggregation. They serve as both reducing agents and capping agents by offering enzymes, peptides, poly(amino acids), polyhydroxyalkanoate, and polysaccharides. In this review, we present an overview of nanoparticle synthesis based on microorganisms including bacteria, fungi, algae, and actinobacteria, encompassing metals such as gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), titanium dioxide ((TiO2), zinc oxide (ZnO), iron oxide (Fe2O3), and selenium (Se). The nanoparticles typically vary in size from 1 to 100 nm and exhibit various shapes including spherical, rod-shaped, triangular, cubic, and hexagonal shapes. Additionally, this review discusses the mechanisms behind the synthesis of metal nanoparticles by microorganisms, whether they occur intracellularly or extracellularly. [ABSTRACT FROM AUTHOR]

Due to the rising human population and industrialization, harmful chemical compounds such as 4-nitrophenol (4-NP) and various dyes are increasingly released into the environment, resulting in water pollution. It is essential to convert these harmful chemicals into harmless compounds to mitigate this pollution. This research focuses on synthesizing a novel heterogeneous catalyst using modified canvas fabric (CF) decorated with silver metal nanoparticles on graphene oxide nanosheets (Ag-GO/CF). The process involves coating the fabrics (CF) with graphene oxide (GO) nanosheets through sonication. Subsequently, silver nanoparticles are deposited in situ and reduced on the GO surface, resulting in the formation of the Ag-GO/CF composite. Various physicochemical characterizations were conducted to examine the interfacial interactions between CF, GO, and Ag nanoparticles. The catalytic activity of the nanocomposite was assessed by hydrogenating 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride (NaBH4). The results showed that the 10%Ag-5%GO/CF with a surface of 6 cm2 (3 × 2 cm) exhibited the highest catalytic activity, achieving a reduction efficiency of over 96% in 5 min. The 4-NP reduction reaction rate was well-fitted with a pseudo-first-order kinetics model with an apparent reaction rate constant (Kapp) of 0.676 min−1. Furthermore, the Ag-GO/CF composite demonstrated remarkable stability over successive cycles, with no noticeable decrease in its catalytic activity, suggesting its promising application for long-term chemical catalytic processes. This synthesized composite can be easily added to and removed from the reaction solution while maintaining high catalytic performance in the reduction of 4-NP, and it could be beneficial in avoiding problems related to powder separation. [ABSTRACT FROM AUTHOR]

Natural rubber–silver-magnetite (NR/Ag–Fe3O4) catalyst was successfully prepared by the incorporation of Ag nanoparticles (AgNPs) into NR-coated Fe3O4 and its formation was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and atomic absorption spectroscopy (AAS) analyses. The catalytic activity of NR/Ag–Fe3O4 was evaluated towards the removal of methyl orange (MO) dye. Different experimental parameters, such as Ag loading, initial dye concentration, and temperature were investigated and discussed in detail. The NR/Ag–Fe3O4 catalyst exhibited excellent catalytic activity for the degradation of MO in the presence of potassium borohydride (KBH4) in aqueous medium. The reaction follows pseudo-first order kinetics. The degradation rate increased with increasing Ag loading and temperature, but decreased with increasing initial dye concentration. The optimized experimental parameters for the degradation process were 2.5 × 10–5 M and 40 °C. The excellent reusability of NR/Ag–Fe3O4 was indicated by the percentage (%) efficiencies of the removal of MO, which were consistently above 95%. Moreover, the lower Fermi energy of the NR/Ag–Fe3O4 catalyst than NR/Fe3O4 suggested that the presence of AgNPs enhanced the conducting properties of NR/Ag–Fe3O4, which led to better electron transfer from KBH4 to MO molecules and higher degradation rate. The presence of the NR/Ag–Fe3O4 catalyst resulted in high mineralization of the MO dye (88.95%), as confirmed by total organic carbon (TOC) analysis. [ABSTRACT FROM AUTHOR]

The development of advanced methods for the synthesis of nano- and microparticles for biomedical applications is of considerable interest. A method for synthesizing submicron silver-shelled calcium carbonate particles using a microfluidic chip designed to control the particle formation is proposed. Precise control of reaction parameters enables controlled formation of silver shell and calcium carbonate particles. The distribution of pores in the hybrid particles was analyzed using small-angle X-ray scattering, which gained insight into the complex structure of the pores. The results provide information on the particle morphology and may facilitate the development of new calcium carbonate-based materials for various applications. [ABSTRACT FROM AUTHOR]

In this work, a novel and versatile route was developed, using Latex copolymer to synthesize pure and silver doped mesoporous Ag/TiO2 (MNps) with various silver contents using two-stage processing method. We investigated the influence of both silver doping content and calcination temperature on the physical features and photocatalytic responses of Ag/TiO2. The Ag/TiO2 nanostructures were characterized using multiple analytical techniques like Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive analysis Scope (EDS), X-Ray Diffraction (XRD), and ultraviolet-visible spectroscopy (UV-Vis). The results indicated that mesoporous Ag/TiO2 are obtained in the form of core-shell structured Nps, Where TiO2 nanoparticles (NPs) had a perfect spherical morphology at 400°C, with a size range of 50 to 300 nm, assembled in an orderly manner with primary nano crystallites of silver on the surface with an average size varying from 5 to 10 nm, forming a. The XRD measurements reported the presence of Anatase TiO2 phase and silver nanoparticles. Photocatalytic studies were carried out in model solutions of water and Methylene Blue (MB) dyes under visible irradiation in presence of pure and metal doped mesoporous Ag/TiO2 (MNps). The samples show a sequential combination of adsorption and photocatalytic dye degradation process with variable reaction rate constants depending on the content of doping silver element. Almost 95% removal of methylene blue was achieved using 5 - 7.5% Ag/TiO2 as a photocatalyst; with a combination of 60% dye adsorption and 35% dye photocatalytic degradation after 60 min of under visible light irradiations. [ABSTRACT FROM AUTHOR]

Pb(II) can accumulate in the body and gradually cause irreversible harm. In this work, a dual-mode colorimetric biosensor based on an aptamer was developed as an effective method for sensitive sensing of Pb(II). The aptamers were immobilized on silver nanoparticles (Ag NPs) by Ag–S bonding to increase the active sites on the electrode surface. Gold–palladium bimetallic nanoparticles (Au@Pd NPs) can not only serve as signal indicators but also play a role as nanozymes. On the one hand, Au@Pd NPs were modified on the aptamer to improve the conductivity of the sensor for the detection of Pb(II) by the electrochemical method of differential pulse voltammetry (DPV). On the other hand, Au@Pd NPs were porous nanomaterials with numerous active sites on their surface that can catalyze the decomposition of hydrogen peroxide (H2O2) in solution to generate O2, so that 3,3′,5,5′-tetramethylbenzidine (TMB) was oxidized to blue oxTMB, enabling the visual prediction of Pb(II). At the same time, with the property that 8–17 deoxyribozyme and metal ions can co-catalyze, it promoted the binding of Au@Pd NPs functionalized aptamer to the electrode in the presence of Pb(II) and enhanced the electrochemical signal. Under optimal conditions, the detection range of Pb(II) was 1—1000 nmol L−1, and the limit of detection (LOD) was 0.4 nmol L−1. The biosensor has been successfully applied to the detection of edible mushroom samples. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag NPs) dispersed in deionized water (DW) are prepared using the Nd:YAG laser ablation method. Transmission electron microscopy (TEM) results were used to investigate the shape and particle size of Ag NPs. The spherical shape and size of about 30 nm are characterized. X-ray diffraction (XRD) analysis shows a good crystallinity of Ag NPs and distinguished peaks at 38° without any impurities. The optical properties of Ag NPs were studied by a UV–visible spectrophotometer, and the surface plasmon resonance was observed at an excitation wavelength of about 402 nm and a direct band gap of about 2.25 eV. The results of the inhibitory activity against Lactobacillus and Streptococcus mutans bacteria indicated areas of high inhibition. The highest inhibition zone was 19 mm at the stock concentration. The anticancer properties of Ag NPs were studied with multi-concentration; the small particle size of Ag NPs led to the killing of about 70% of the MCF-7 line; and the inhibitory concentration (IC50) of Ag NPs was about 93.55 µg/mL−1. [ABSTRACT FROM AUTHOR]

Herein, a study on the chitosan-amalgamated gold nanoparticles (AuNPs)- and silver nanoparticles (AgNPs)-based molecularly imprinted polymer (MIP) film and its application to recognize/remove ciprofloxacin (CIP) antibiotic in real samples is reported. The pomegranate peel at pH 8 is used for the reduction of silver nitrate solution to form AgNPs, whereas chitosan itself is used for the reduction of gold chloride solution to form AuNPs. The size of the synthesized AgNPs and AuNPs is in the range 30–45 and 45–50 nm, respectively, which is determined by dynamic light scattering (DLS). Further, the synthesized nanoparticles (NPs) are used to prepare MIP film. The molecularly tailored chitosan-based nanocomposite is used as a functional biopolymer to enhance the adsorption capacity and surface area of MIP film. The properties of synthesized chitosan-based AuNPs- and chitosan-based AgNPs-MIP composite (Chi@AuMIP and Chi@AgMIP) exhibited much higher adsorption capacity than non-imprinted polymer (NIP). The results revealed that the theoretical equilibrium constant (KL) and maximum adsorption capacity (Qmax) found by the Langmuir model are 12.2 and 20.48 mg g−1 for Chi@AuMIP and 18.31 and 34.13 mg g−1 for Chi@AgMIP, respectively. The recovery percentage of CIP for Chi@AuMIP and Chi@AgMIP is 98 and 80%, respectively. The selectivity experiment data suggest maximum adsorption capacity for targeted molecule (CIP) by the MIP as compared to analogs of template molecule. MIP showed relative potential selectivity and good recovery percentage for CIP in real samples as well. [ABSTRACT FROM AUTHOR]

Background: Silver nanoparticles are widely used in various fields such as industry, medicine, biotechnology, and agriculture. However, the inevitable release of these nanoparticles into the environment poses potential risks to ecosystems and may affect plant productivity. Coronatine is one of the newly identified compounds known for its beneficial influence on enhancing plant resilience against various stress factors. To evaluate the effectiveness of coronatine pretreatment in mitigating the stress induced by silver nanoparticles on cress plants, the present study was carried out. Results: Our findings indicated a decrease in multiple growth parameters, proline content, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in cress plants exposed to silver nanoparticle treatment. This decline could be attributed to the oxidative stress induced by the presence of silver nanoparticles in the plants. Conversely, when coronatine treatment was applied, it effectively mitigated the reduction in growth parameters and pigments induced by the silver nanoparticles. Furthermore, we observed an increase in silver content in both the roots and shoot portions, along with elevated levels of malondialdehyde (MDA) content, hydrogen peroxide (H2O2), anthocyanins, glutathione (GSH), and antioxidant enzyme activities in plants exposed to silver nanoparticles. Concurrently, there was a decrease in total phenolic compounds, ascorbate, anthocyanins, and proline content. Pre-treatment of cress seeds with coronatine resulted in increased levels of GSH, total phenolic compounds, and proline content while reducing the silver content in both the root and shoot parts of the plant. Conclusions: Coronatine pre-treatment appeared to enhance both enzymatic and non-enzymatic antioxidant activities, thereby alleviating oxidative stress and improving the response to stress induced by silver nanoparticles. [ABSTRACT FROM AUTHOR]

The paper discusses the results of the electrosynthesis of metal–polymer nanocomposites of silver and coatings on pure iron and steel electrodes by combining the process of electropolymerization of 1-vinyl-1,2,4-triazole (VT) with N-vinyl-caprolactam (VC) and cathodic precipitation of metals. During the electrolysis of aqueous and water–ethanol solutions of VT with VC at various ratios in the presence of AgNO3, metal nanocomposites and coatings are formed on purely iron and steel electrodes. The structure and composition of the synthesized metal nanocomposites were confirmed by various physicochemical methods, such as electron and IR spectroscopic, X-ray phase and thermogravimetric, elemental analyses, as well as by transmission electron microscopy. In the electronic spectra of nanocomposites, absorption bands appear with a maximum at 405–421 nm, which is typical for systems with zero-valent silver. The IR spectra show that the matrix structure hardly changes during the formation of nanocomposites and coatings. At high current densities (j ≥ 10 mA/sm2), nanocomposite films are formed on the electrode surface. The silver content in nanocomposites is 0–9%, which leads to an increase in the viscosity of nanocomposite solutions compared to solutions of the initial copolymers. Increasing the silver content above 8% will lead first to a partial and then to a complete loss of solubility. According to the data of transmission electron macroscopy, the synthesized polymer nanocomposites consist of isolated silver nanoparticles, predominantly spherical in shape, uniformly distributed in the bulk of the polymer matrix. The size dispersion of nanoparticles depends on the silver content in the nanoparticles. The thermal decomposition of metal nanocomposites occurs in stages. [ABSTRACT FROM AUTHOR]

The direct nanoimprinting of silver nanoparticles (Ag NPs) generated a plasmonic metallic nanostructure. The Ag NPs used in this study have been synthesized by a phase transfer method. The procedure comprised the utilisation of sodium borohydride to reduce silver nitrate in the presence of a stabilizing agent, which facilitated the transfer of the NPs from the aqueous phase to an organic phase, resulting in uniform and stable particles. The size and shape of the Ag NPs were characterized using electron microscopy, revealing spherical particles with an average diameter of 9 nm. The XRD examination revealed that the nanoparticles exhibit a high degree of crystallinity and possess a cubic geometric phase. The UV-visible absorption spectra demonstrate a significant level of homogeneity in the size. The silicon surface imprinted with Ag NPs exhibits hydrophobic behaviour towards water molecules. This approach allows for precise control of Ag NPs on the substrate, resulting in a robust and effective platform for future applications in sensor technology. Furthermore, the hydrophobic nature of the imprinted surface suggests potential applications in water-repellent coatings or self-cleaning materials. [ABSTRACT FROM AUTHOR]

Interfacial solar steam generation is a potential technology to relieve the freshwater shortage. However, developing a cost-effective method to design photo-absorbers with steady desalination performance remains a significant challenge. In this study, we designed, the Polyvinyl Alcohol (PVA): Glutaraldehyde (GA)/silver and gold plasmonic nanoparticle/activated carbon hydrogel nanocomposite as sponge-like photo-absorber materials. Glutaraldehyde (GA) as a simple chemical crosslinking added to PVA/AC hydrogel along with to Au or Ag nanoparticles for increasing the light absorption. The optical properties results show that by adding gold and silver nanoparticles as plasmonic agent in this hydrogel, the light absorption is increased in wet hydrogel which can reach 74% with water evaporate rate of 5.58 kg−2 m−2 h−1. The PVA: GA: Au hydrogel (AC) nanocomposite shows a steady evaporation rate of about 5.08 kg−2 m−2 h−1 under 0.1 solar intensity during desalination. The 24 h of indoor desalination experiments proves that both hydrogel is durable and has a steady evaporation performance. The PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite hydrogels were characterized by XRD analysis, FE-SEM imaging, UV–Vis and FTIR spectroscopy. The XRD results for PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite showed that the amorphous pattern decreased sharply due to a decrease in the PVA peak. Also, the both peaks of Au and Ag with the tetragonal and cubic structures were observed with the preferred direction (110). FE-SEM images of PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite showed micro pores on the surface of hydrogels and porous structure of the hydrogel network is formed. Also, the results of FTIR spectroscopy showed that with increasing metal nanoparticles, there is no difference in the type of a factor group and only affects the intensity of the peaks and leads to a little shift of the peaks to the modes of pure PVA. The PVA:GA: Au (Ag) hydrogel (AC) nanocomposite offers a substantial possibility in mitigating freshwater shortages. [ABSTRACT FROM AUTHOR]

As the next generation of die attachment technology, sintering bonding using silver nanoparticles is attracting great interest for application in power electronics packaging. For organic-free silver nano-sintering materials, increasing the oxygen content facilitates the sintering process but also causes oxidation of the substrate and other components. In this work, organic-free silver nanostructured film was utilized to bond the SiC chips and the substrate with three types of metallization: (1) electroless nickel immersion gold finishing substrate (ENIG), (2) Ag-coated substrate, and (3) bare Cu substrate. The bonding process was conducted at low temperature (150–300°C), and the effects of oxygen on the microstructure, bonding quality of the interfaces and fracture morphology were studied. Oxygen significantly facilitated the sintering process of the Ag nanoparticles in the film, which promoted the densification of the bondline, even at low concentrations (0.05%). In addition, the facilitating effects of oxygen were detected at content of 0.05% during the sintering between Ag nanoparticles and the three types of metallized substrate. However, at higher oxygen content (≥5%), the sintering behavior varied among the different substrate metals. The Ag-coated substrate surface roughened in situ at high oxygen content and showed positive effects on the bonding strength, while the ENIG substrate surface was inert to oxygen. The bare Cu substrate surface showed complex oxide states at different oxygen concentrations. The Cu2O phase formed at oxygen content of ≤ 5%, which enhanced the bonding strength, while CuO tended to appear at oxygen content of ≥ 20%, which reduced the bonding strength. These results reveal that relatively low oxygen content (0.05%) can effectively improve bonding strength while avoiding oxidation of the Cu substrate. [ABSTRACT FROM AUTHOR]

This paper presents the syntheses of SiO2 particles immobilized with Ag nanoparticles and their composite with Au. Ag nanoparticles are present on the surfaces of the SiO2 particles, and Ag+ ions are galvanically replaced with Au3+ ions. Finally, a method for maintaining the color durability and dispersibility of the Ag nanoparticles is demonstrated. The particles are primarily synthesized in three steps: In the first step, Sn2+ ions are adsorbed on the surfaces of the SiO2 particles; in the second step, Ag+ ions are added, which are reduced and simultaneously adsorbed on the surface while Sn2+ is oxidized to Sn4+; in the third step, Au3+ ions are reduced by galvanic replacement and deposited on the Ag surface. Extensive characterization using transmission electron microscopy, scanning transmission electron microscopy, ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy reveals that the Ag–Au composite nanoparticles (17.2 ± 4.1 nm) are immobilized on the surface of the SiO2 particles (<1 µm). The morphology and coloration of the SiO2 particles with the immobilized Ag–Au composite nanoparticles remain preserved in nitric acid. This preservation is more pronounced than that observed in SiO2 particles with immobilized Ag nanoparticles. This enhanced durability can be attributed to the formation of stable bonds between Ag and Au. [ABSTRACT FROM AUTHOR]

Ag(Pd) bimetallic nanostructures (Ag(Pd)NPs) were synthesized using the galvanic replacement of palladium ions with silver nanoparticles. Based on a comparative analysis of the results of scanning electron microscopy, energy dispersive X-ray microanalysis, and X-ray powder diffraction, it was established that the obtained Ag(Pd)NPs can be considered as "core-shell" nanosystems, in which the core is silver, and the shells are palladium nanoparticles with a size of 5–15 nm. Ag(Pd)NPs were studied as catalysts for the aerobic liquid-phase oxidation of benzyl alcohol. The addition of Ag(Pd)NPs to the reaction system accelerates the reaction in 14 times. [ABSTRACT FROM AUTHOR]

Schiff base compounds were reported to make a complex with Cu2+ and Ag+ and subsequent reduction produced Cu0 and Ag0 nanoparticles separately via UV irradiation. Here, we synthesized a Schiff base, which initially formed a complexation with Cu2+ and made Cu0 nanoparticles after 8 h aging. In that reaction mixture, addition of Ag+ resulted in Ag0 nanoparticles. Emissive semi-carbazone (a Schiff base synthesized from semicarbazide and salicylaldehyde) was employed for the first time to selectively and sensitively detect Cu2+ (linear range of detection 10–4 to 5 × 10–8 M and limit of detection 13 μM) with the formation of copper oxide nanoparticles via complexation–reduction method. The introduction of Ag+ in it produced Ag0 and Cu0 (CuO via aerial oxidation) nanoparticles with a gigantic increase of fluorescence to obtain selective and sensitive Ag+ detection (linear detection range 10–3–10–7 M, and limit of detection 7. 7 μM). Thus, Cu2+ and Ag+ were detected based on turn-off/on fluorescence in one pot. As the evolution of copper and silver nanoparticles was the fundamental reason for sensing, response time is similar to the stable fluorescence behavior of oxidized SC (capping agent) with in situ generated copper and silver nanoparticles. CuO-induced fluorescence quenching was due to the formation of the trapped plasmon, while Ag+-induced fluorescence enhancement was owing to the lightning rod effect. The synergism of Cu and Ag was also investigated in this paper as a driving force of the lightning rod effect for the first time. Both the metals (Cu and Ag) were estimated in natural water, justifying the utility of the sensing platform for practical applications. Besides, the evolution of brilliant red color with semi-carbazone for Ag+ was employed for the colorimetric sensing of Ag+. [ABSTRACT FROM AUTHOR]

Using a mixture of micro-copper and nano-silver in the production of screen-printed circuits has the potential to reduce material costs and cost variability. The fundamental premise of this study involved dispersing silver nanoparticles among the larger copper microparticles at selected ratios and subsequently sintering in order to establish their resultant electrical and physical performance. Commercial materials were mixed, printed, and sintered at two thermal regimes on fluorine-doped tin oxide (FTO)-coated glass substrate. The inclusion of 25% silver provided an appreciable reduction in electrical resistance from 4.21 Ω to 0.93 Ω, with further silver additions having less impact. The thermal regime used for sintering had a secondary impact on the final electrical performance. The addition of silver reduced the adhesion to the FTO substrate, with reduced film integrity. The results show that blending inks offers the advantage of enhancing material conductivity while simultaneously reducing costs, making it a compelling area for exploration and advancement in the field of electronics manufacturing. [ABSTRACT FROM AUTHOR]

Novel formulations of silver nanoparticles remain exciting if it is applicable for cosmetic purposes. This study proposes a value-added brand-new nanomaterial for improving skin complexion by inhibiting melanin development. This work aims to develop cost effective, efficient, natural silver nanoparticles phytomediated by aqueous extract of leaf sheath scales of Cocos nucifera (Cn-AgNPs) having potential as tyrosinase inhibitors hindering melanin synthesis. The formation of Cn-AgNPs was assessed spectrophotometrically and confirmed by the sharp SPR spectrum at 425 nm. The chemical composition profiling was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The morphology was confirmed by Field Emission Scanning Electron Microscopy (FESEM) and the thermal stability was assessed by Thermogravimetric analysis (TGA). Pharmacological application studies supported the materialization of Cn-AgNPs with significant antityrosinase potential and considerably improved antibacterial and antioxidant properties. Cn-AgNPs showed potential antibacterial effects against gram-positive and negative strains, including prominent infectious agents of the skin. Antioxidant capacity was confirmed with an IC50 of 57.8 μg/mL by DPPH radical scavenging assay. Furthermore, in vitro melanin content determination was performed using SK-MEL cells. Cell line studies proved that Cn-AgNPs decrease the melanin content of cells. The IC50 value obtained was 84.82 μg/mL. Hence Cn-AgNPs is proposed to be acting as a whitening agent through lessening cellular melanin content and as a significant inhibitor of tyrosinase activity. The antioxidant properties and antibacterial effects can contribute to skin rejuvenation and can prevent skin infections as well. This evidence proposes the development of a new nanostructured pharmaceutical and cosmetic formulation from Cocos nucifera leaf sheath scales. [ABSTRACT FROM AUTHOR]

The development of an effective and eco-friendly silver nanoparticle (AgNPs) to abate the effect of abiotic stress is an important area of nano-biotechnology. This study aimed to study the priming effect of plant-based green-synthesized silver nanoparticles and melatonin on the physiological and biochemical activities of drought-stressed E. uniflora. Sterilized seeds of E. uniflora were primed with 0.06 mg/l of ML-AgNPs, 0.06 mg/l of melatonin, and a nano-silver formulation of melatonin (1:1). Primed seeds were planted and subjected to 7 days under drought stress. The ML-AgNPs enhanced germination percentage, speed and vigor, and shoot elongation and induced the production of APx, CAT, and proline dehydrogenase (100% increases). Melatonin improved the activities of APx and CAT, total protein, accumulation of proline, and proline dehydrogenase (200% increases) and stabilized MDA content. Meanwhile, silver nano-formulation of melatonin increased leaves proliferation of leaves and production of APx, GPx, SOD, and CAT. Accumulation of proline and 100% upregulation of proline dehydrogenase osmo-regulated the effects of the drought, reduced MDA contents, and stabilized the excessive production of H2O2 and O2−. The ML-AgNO3 showed an efficient delivery system of melatonin into the plant under drought stress. As a result, our research shows that melatonin in silver nano-formulation (1:1) is a useful biostimulant against drought stress. [ABSTRACT FROM AUTHOR]

Polymer nanocomposite materials with catalytic activity were designed via modification of MF-4SK ion-exchange membranes with Au and Ag nanoparticles obtained according to various synthetic methods in reverse micellar solutions. A sufficient transparency of the films allowed us to detect nanoparticles in the films using UV–Vis spectrophotometry, monitoring changes in the content of metal nanoparticles in the reverse micellar solution. A different mechanism of interaction of Au and Ag nanoparticles obtained by the same synthetic method with the MF-4SK film upon their contact with its surface was discovered, the destruction of nanoparticles was observed, and the influence of mechanism of primary acts in the formation of metal nanoparticles in reverse micellar solutions on their adsorption properties was confirmed. The highest concentration of gold nanoparticles was found in films immersed in reverse micellar solutions at the time of their exposure to ionizing radiation. [ABSTRACT FROM AUTHOR]

Silver (Ag) paste is widely used in semiconductor metallization, especially in silicon solar cells. Ag powder is the material with the highest proportion in Ag paste. The morphology and structure of Ag powder are crucial which determine its characteristics, especially for the sintering activity. In this work, a simple method was developed to synthesize a type of microcrystalline spherical Ag particles (SP-A) with internal pores and the structural changes and sintering behavior were thoroughly studied by combining ultra-small-angle X-ray scattering (USAXS), small-angle X-ray scattering (SAXS), in-situ heating X-ray diffraction (XRD), focused ion beam (FIB), and thermal analysis measurement. Due to the unique internal pores, the grain size of SP-A is smaller, and the coefficient of thermal expansion (CTE) is higher than that of traditional solid Ag particles. As a result, the sintering activity of SP-A is excellent, which can form a denser sintered body and form silver nanoparticles at the Ag–Si interface to improve silver silicon contact. Polycrystalline silicon solar cell built with SP-A obtained a low series resistance (Rs) and a high photoelectric conversion efficiency (PCE) of 19.26%. These fill a gap in Ag particle structure research, which is significant for the development of high-performance electronic Ag particles and efficient semiconductor devices. [ABSTRACT FROM AUTHOR]

Gold and silver nanoparticles have witnessed increased scientific interest due to their colourful colloidal solutions and exceptional applications. Comparing the localized surface plasmon resonance (LSPR) of gold and silver nanoparticles is crucial for understanding and optimizing their optical properties. This comparison informs the design of highly sensitive plasmonic sensors, aids in selecting the most suitable nanoparticles for applications like surface-enhanced infrared spectroscopy (SEIRA) and biomedical imaging, and guides the choice between gold and silver nanoparticles based on their catalytic and photothermal properties. Ultimately, the study of LSPR facilitates the tailored use of these nanoparticles in diverse scientific and technological applications. Two SEIRA methods combined with partial least squares regression (PLSR) chemometric tools were developed. This development is based on the synthesis of homogeneous, high-dense deposited metal nanoparticle islands over the surface of glass substrates to be used as lab-on-chip SEIRA sensors for the determination of bisacodyl (BIS) and its active metabolite in plasma. SEM micrographs revealed the formation of metallic islands of colloidal citrate-capped gold and silver nanoparticles of average sizes of 29.7 and 15 nm, respectively. BIS and its active metabolite were placed on the nanoparticles' coated substrates to be directly measured, then PLSR chemometric modelling was used for the quantitative determinations. Plasmonic citrate-capped gold nanoparticle substrates showed better performance than those prepared using citrate-capped silver nanoparticles in terms of preparation time, enhancement factor, PLSR model prediction, and quantitative results. This study offers a way to determine BIS and its active metabolite in the concentration range 15–240 ng/mL in human plasma using inexpensive disposable glass-coated substrates that can be prepared in 1 h to get results in seconds with good recovery between 98.77 and 100.64%. The sensors provided fast, simple, selective, molecular-specific and inexpensive procedures to determine molecules in their pure form and biological fluid. [ABSTRACT FROM AUTHOR]

Occupational health must be strictly considered in industries particularly in nanoparticle factories where workers were exposed to different types of chemicals. We measured the serum levels of inflammatory cytokines in workers who developed skin lesions after exposure to silver and silica nanoparticles. Using a questionnaire in this cross-sectional study, we identified 110 workers in nanoparticle industries who were exposed to silver and silica nanoparticles. We also included 40 healthy subjects as controls from the administrative department of the same factories who were not exposed to nanoparticles. Peripheral blood samples used to measure the mRNA levels of inflammatory cytokines by qRT-PCR. In comparison with the control group, the workers who developed skin lesions had significantly higher levels of interleukin IL4, IL6, IL8, and TNF-α, particularly after two or three decades of exposure to silver and silica nanoparticles. Participants who were exposed to silver had higher levels of IL6 and IL8 compared with those who were exposed to silica. Necessary measures must be considered to protect workers in nanoparticle industries against the potential toxic effects of these compounds. Our network pharmacology study suggests corresponding biochemical pathways for these disorders. [ABSTRACT FROM AUTHOR]

Toxicological effects of silver nanoparticles (SNPs) in different organisms have been studied; however, interactions of SNPs with other environmental pollutants such as mercury are poorly understood. Herein, bioassay tests were performed according to ΟECD 201 guideline to assess the toxic effects induced by mercury ions (mercury chloride, MCl) on the marine microalga Chaetoceros muelleri in the presence of SNPs or silver ions (silver nitrate, SN). Acute toxicity tests displayed that the presence of SNPs or SN (0.01 mg L−1) significantly reduced the toxicity of MCl (0.001, 0.01, 0.1, 1, 10, and 100 mg L−1) and increased the IC50 of MCl from 0.072 ± 0.014 to 0.381 ± 0.029 and 0.676 ± 0.034 mg L−1, respectively. In the presence of SN or SNPs, the mercury-reducing effect on algal population growth significantly decreased. Considering the increase of IC50, the mercury toxicity decreased approximately 5.44 and 9.66 times in the presence of SNPs or SN, respectively. The chlorophyll a and c contents decreased at all exposures; however, the decrease by MCl-SNPs and MCl-SN was significantly less than MCl except at 1 mg L−1. The lowering effect of MCl-SN on chlorophyll contents was less than MCl and MCl-SNPs. MCl exposure induced significant raises in total protein content (TPC) at concentrations < 0.01mg L−1, with a maximum of ~ 70.83% attained at 100 mg L−1. The effects of MCl-SNPs and MCl-SN on TPC were significantly less than MCl. Total lipid content (TLC) at all MCl concentrations was higher than the control, while at coexposure to MCl-SN, TLC did not change until 0.01 mg L−1 compared with the control. The effects of MCl-SN and MCL-SNPs on TPC and TLC were in line with toxicity results, and were significantly less than those of MCl individually, confirming their antagonistic effects on MCl. The morphological changes of algal cells and mercury content of the cell wall at MCl-SN and MCl-SNPs were mitigated compared with MCl exposure. These findings highlight the mitigatory impacts of silver species on mercury toxicity, emphasizing the need for better realizing the mixture toxicity effects of pollutants in the water ecosystem. [ABSTRACT FROM AUTHOR]

The combination of ultrasound and microreactors for the synthesis of nanomaterials is becoming increasingly popular, but effectively altering the ultrasonic field at the microscale to control the crystallization process remains a challenge. Herein, we investigated numerically and experimentally the effects of the ultrasonic field on the synthesis of boron-doped carbon nitride supported silver nanoparticles based on our homemade ultrasound-assisted coiled flow inverter microreactor (UCFIR). Specifically, the ultrasound promotes the radial mixing in the coiled flow inverter microreactor, even under low Reynolds number 10, resulting in better control over the crystallization process. The effects of key parameters, such as ultrasonic field distribution and ultrasonic power, on the particle size and size distribution of Ag/B-g-C3N4 have been demonstrated. The results show that when the ultrasound transducer is positioned on the 'abc' sides, the Ag/B-g-C3N4 with small and uniform Ag particles (4.12 ± 1.12 nm) can be obtained. As ultrasound power increased (0–176 W) and residence time decreased (17.5–140 s), the size of silver nanoparticles decreased, and their distribution narrowed. [ABSTRACT FROM AUTHOR]

New silver complexes [Ag(bipy)(CH3COCHCOR)]x with 2,2′-bipyridine (bipy) and β-diketonate ligands (tfac: R = CF3, x = 2; hfbac: R = C3F7, x = 1) are prepared as part of the search for precursors for the vapor deposition of films and silver nanoparticles. The compounds are characterized by elemental analysis, IR and 1H NMR spectroscopy; their crystal structures are determined by XRD. Both complex are molecular due to the bidentate-cyclic coordination of both ligands. The [Ag(bipy)(hfbac)] molecules are mononuclear due to the steric effect of the extended perfluoroalkyl chain. For L = tfac, a binuclear complex is formed due to the coordination of the methine carbon atom. Thermal properties of the new complexes are studied by TGA and DSC and compared with those of the known hexafluoroacetylacetonate analog [Ag(bipy)(hfac)]2. The temperatures and thermodynamic parameters of melting are determined for all the studied compounds. [ABSTRACT FROM AUTHOR]

Polyethylene glycol-6000 (PEG-6000) and trisodium citrate dihydrate (TSC) form an aqueous two-phase system (ATPS). This ATPS has been explored for synthesis and separation of silver nanoparticles (AgNPs). However, synthesis of stable nanoparticles using high TSC concentration corresponding to generic ATPS composition is not possible as high ionic strength of TSC causes aggregation and precipitation of silver nuclei. In the current study, this problem was overcome by synthesizing AgNPs at low concentrations of TSC. A two-step process was used for simultaneous synthesis and separation of AgNPs. Once stable nanoparticles were synthesised at low TSC concentration, the solution was taken to biphasic ATPS composition by mixing higher concentrations of TSC and PEG-6000 solutions to ensure particle entrapment. A silver to TSC (Ag+:TSC) molar ratio ≥ 67 × 10–3 that corresponds to lower TSC concentrations resulted in the formation of stable silver nanoparticles. The synthesis was carried out in batch and continuous modes. Spherical particles of average size 9.1 ± 3.4 nm were obtained in batch mode while in the continuous mode, the size was 10.6 ± 2.5 nm. Addition of polyvinylpyrrolidone (PVP) helped in sterically stabilizing the particles. Spontaneous formation and stabilization of AgNPs were observed within 15 min of reaction time as opposed to several hours reported in literature. The adopted synthesis route thus, is an effective green process to synthesise stable nanoparticles of silver which can be used in biological applications. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNP) can help prevent infection of virus and bacteria. The size and morphology of AgNP can be crucial to function, with smaller nanoparticles (< 20 nm) able to penetrate the cell wall. This is significant as oxidative stress and genotoxicity are associated with some sizes and coatings of AgNP, contraindicating the use of AgNP to reduce infection. We present evidence that a microfluidic chip can synthesize larger sizes and distributions of AgNP from the nano-to-micro size range. We show results from a microfluidic mixing chip that can produce a wide range of nano-to-micro size (~ 24–400 nm) AgNP. Synthesis is based on a modified Turkevich method, using a single-step AgNP synthesis on the microfluidic chip using two chemical components, trisodium citrate (NaCit) and AgNO3. To make AgNP more accessible, we describe the microfluidic chip and conditions capable of synthesis. We also describe how modification of flow rate and chemical reagent concentration change particle diameter during production. In our experiments, we found that AgNP production created a visible adsorption line in the microfluidic device, possibly owing to AgNP surface interaction at the polydimethylsiloxane (PDMS) interface. We characterize these particles with dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Based on optical light microscopy, we hypothesize that AgNP formation primarily occurs at the interface between the two chemical reagent streams. We also conclude that AgNP size increases could be due to interaction with the PDMS surface, which is known to be porous. Future work will help to understand how surface interaction may influence the formation of larger particles. [ABSTRACT FROM AUTHOR]

Since thermoelectric materials have different physical and chemical properties, the design of contact layers requires dedicated efforts, and the welding temperatures are distinctly different. Therefore, a general interface design and connection technology can greatly facilitate the development of thermoelectric devices. Herein, we proposed a screening strategy for the contact materials based on the calculation of phase diagram method, and Mg2Ni has been identified as a matched contact layer for n-type Mg3Sb2-based materials. And this screening strategy can be effectively applied to other thermoelectric materials. By adopting the low-temperature sintering silver nanoparticles technology, the Zintl phase thermoelectric device can be fabricated at low temperature but operate at medium temperature. The single-leg n-type Mg3.15Co0.05SbBi0.99Se0.01 device achieves an efficiency of ~13.3%, and a high efficiency of ~11% at the temperature difference of 430 K has been realized for the Zintl phase thermoelectric device comprised together with p-type Yb0.9Mg0.9Zn1.198Ag0.002Sb2. Additionally, the thermal aging and thermal cycle experiments proved the long-term reliability of the Mg2Ni/Mg3.15Co0.05SbBi0.99Se0.01 interface and the nano-silver sintering joints. Our work paves an effective avenue for the development of advanced devices for thermoelectric power generation. Based on the CALPHAD method, authors propose an effective screening strategy for thermoelectric contact materials, realizing a high efficiency of ~11% (at ∆T = 430 K) for the full-Zintl phase thermoelectric device. [ABSTRACT FROM AUTHOR]

Selective and sensitive detection of halides in water is critically important in the diagnosis of diseases and assessment of aquatic ecosystems. The recognition is usually carried out by numerous analytical techniques such as ion chromatography, fluorescence, near-infrared spectroscopy, ion-selective electrode and light scattering. Although these methods offer high sensitivity, they are expensive and time-consuming. Therefore, great efforts have been focused on the sensing of halide anions in water through a simple, fast, low-cost and portable paper-based colorimetric platform. In particular, the sensing process with silver nanoparticles interacting with analytes is of great chemical and biological interest. In this work, anisotropic silver nanoparticles in size and shape embedded in epoxy resin were prepared and subsequently printed on filter papers of cellulose. The influence of water and halide anions (Cl−, Br− and I−) on the morphology of these nanoparticles are investigated by scanning electron microscopy, Raman shift and diffuse reflectance spectroscopy. The mechanism involves aggregation of faceted silver nanoparticles induced by interactions between carbonyl groups of the resin and water. Subsequently, the interaction between halide anions and the aggregated silver nanoparticles causes oxidative etching on their surface, shape conversion (faceted to quasi-spherical shapes), decreasing in the particle size and formation of chain–like or compact aggregates resulting in strong interparticle plasmonic coupling. This selective mechanism was tested for the naked-eye colorimetric recognition of chloride anions in a complex simulated physiological system, whose results show promising perspectives to develop diagnostic-sensing devices. [ABSTRACT FROM AUTHOR]

This study focuses on tumor therapy using two biocompatible silver nanoplatforms of chamomile extract and its active ingredient apigenin-7-glucoside. Chamomile silver nanoparticles (Ch-AgNPs) and apigenin 7- glucoside silver nanoparticles (Ap-AgNPs) were synthesized and characterized using different analytical techniques. On a stable nanoplatform with spherical nanoparticles in a narrow size range, both Ch-AgNP and Ap-AgNP exhibit potent cytotoxic effects against two different cell lines (HepG2 and MCF7). The synthesized NPs were radiolabeled with 131I giving high radiochemical purity. Biodistribution studies in tumor-bearing Albino mice showed higher accumulation in tumor sites compared to normal muscle. In conclusion, after further preclinical studies, both chamomile silver nanoparticles (Ch-AgNPs) and apigenin-7-glucoside silver nanoparticles (Ap-AgNPs) can be used as potential drugs for tumor theranostics. [ABSTRACT FROM AUTHOR]

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

Current work presents a detailed study on the synthesis of silver nanoparticles (70 ± 5 nm) functionalized with 4-mercaptobenzoic acid and their interaction with divalent ions (Cu2+, Fe2+, Co2+, Ni2+, Pb2+, Mn2+, Zn2+, Sn2+). The study reveals the morphological changes in the nanoparticles due to interaction with Cu2+, resulting in the formation of larger nanoparticle aggregates. The UV-Vis spectra of the pristine and aggregated nanoparticles are also discussed, providing insights into the changes in their optical properties. These nanoparticles are used to detect divalent ions using surface-enhanced Raman spectroscopy with a detection limit of 2.5 × 10–7 M for Cu2+ and also show a linear response within the 10–3 to 10–7 M concentration range. High selectivity for Cu2+, Fe2+, Co2+, Mn2+, and Pb2+ was also detected. The findings of this study could have significant implications in the field of nanomaterials and environmental chemistry, particularly in the detection and removal of heavy metal ions. [ABSTRACT FROM AUTHOR]

A polyvinylpyrrolidone-capped (PVP-capped) strategy is reported to synthesize Ag NPs on silicon wafers via galvanic replacement reaction for SERS detection of adenine, where PVP acts as stabilizing agent in synthesis and efficient enrichment in detection. The morphologies of Ag NPs are optimized with uniform particle size by adjusting synthesis conditions, which hold excellent SERS performances like a high enhancement factor of 1.42 × 106, good uniform, reproducibility, and transferable nature. With the protection of the capped PVP, the Ag NPs keep excellent SERS properties even against harsh conditions of high temperature (100 ℃) and strong acid and base for 24 h. Utilizing the structural feature of PVP with abundant carbonyl groups, the PVP-capped Ag NPs achieve efficient enrichment of adenine through hydrogen bonding and π-interactions, which is analyzed by density functional theory. Quantitative detection of adenine is performed with a wide linear range from 10−4 to 10−8 M and a low limit of detection of 1 nM. Detection of adenine in human urine samples is achieved with a recovery of 99.1–103.4% and an RSD of less than 5%. [ABSTRACT FROM AUTHOR]

Three types of silver/silver chloride nanoparticles were obtained by green synthesis from three types of microbial biomass. Their biocidal capacity was tested against six microorganisms. Two filamentous fungi were used that had previously demonstrated the ability to synthesise nanoparticles, Penicillium sp. 8L2 and Botryosphaeria rhodina MAMB-05. Also, the synthesis capacity of a yeast, Rhodotorula mucilaginosa 1S1, was evaluated. The original protocols underwent slight modifications. At the same time, the fractional inhibitory concentration was obtained. The interaction between specific antibiotics and the nanoparticles that showed the greatest biocidal capacity came from Penicillium sp.8L2, and it was studied further. All nanoparticles were characterised by UV–vis spectrophotometry and transmission electron microscopy (TEM). Also, their size distribution was analysed, which was in the range of 4 to 34 nm. The biocidal capacity of the nanoparticles for a group of bacteria and fungi was studied, presenting very low values in the range of 2.5–10 µg/mL for bacteria and 4–256 µg/mL for fungi. The interactions between the nanoparticles synthesised by Penicillium sp. 8L2 and a group of specific antibiotics for the tested microorganisms were also studied, proving that there was a synergistic interaction with vancomycin and ciprofloxacin and Staphylococcus epidermidis CECT 4183 and Escherichia coli CECT 101 bacteria, respectively. [ABSTRACT FROM AUTHOR]

This work presents the preparation of Ag@ Cu2O nano-crystals employing two methods, laser ablation in liquid and photo-ionization using UV radiation as a light source. The effect of Ag concentration on optical, electrical, structural, surface morphology, and other physical properties of Ag@Cu2O crystal was carried out. This work provides an on-site technique for the homogeneous development of Ag NPs on Cu2O surfaces, which involves the use of low-cost Ag salts as the source of Ag plasmonic nanoparticles. The Ag concentration was taken as a function of different chemical interaction times (5–25) sec that were used to adsorb the Ag nanoparticles (NPs) on the surface of the Cu2O sample. The optical properties ensure the improvement of the prepared material with the presence of Ag plasmonic nanoparticle, where the estimated energy gap was found to be reduced from 1.9 to 1.66 eV, and a red-shift in the optical spectra has been recognized. The surface morphology obtained by SEM images ensured the formation of a fine, smooth, uniform structure, and revealed that Ag nanoparticles have quasi-spherical morphologies with an average particle size ranging from 62 to 32 nm, based on the immersion times. Structural properties proved the formation of cubic Cu2O crystal centered at (110) diffraction plane. This was attributed to the Raman results. The optimum properties of Ag@Cu2O were obtained at 15 s, reduction of the optical band gap to 1.8 eV, and additionally, it offered the highest merit rating (F.O.M.) with an electrical conductivity of 2.09 S cm−2. [ABSTRACT FROM AUTHOR]