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Recently, designing and fabricating effectual wound dressings have gained a great deal of interest for the proper management of wound infections and biofilms. The present study is focused on the fabricating and characterizing silver chloride-loaded polyvinyl alcohol nanofibers as antibacterial and conductive wound dressing scaffold by electrospinning technique. Polyvinyl alcohol was subjected to the electrospinning process, and silver chloride was incorporated within PVA nanofibers via in situ reaction between silver nitrate and sodium chloride during the fiber-forming process. The obtained silver-free and silver chloride-containing nanofibers were characterized by different techniques, including scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (DSC and TGA), etc. The gravimetric method and tensile testing were used to determine the porosity and mechanical properties of the fabricated nanofibers. The nanofiber's in vitro degradation, swelling, and water retention properties were assessed, and their drug loading and release profiles were evaluated by the atomic absorption spectrometry (AAS) method. The wound healing characteristics of the obtained nanofibers, such as antibacterial activity, hemocompatibility, electrical conductivity, and cytotoxicity were evaluated in vitro. The results of this study confirmed that the silver chloride-containing nanofibers exhibit desired physicochemical, morphological, and mechanical properties and could be considered as a potential wound dressing for the management of infectious wounds. On the other hand, the obtained nanofibers showed higher hemocompatibility (less than 5% hemolysis ratio) and cell viability (over 80% after 48 h) as well as appropriate antibacterial activity against two representative strains of Gram-positive and Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

Non‐invasive electrodes for recording and delivering electric signals to the human body are crucial for health monitoring and rehabilitation applications. However, high‐fidelity signal recording or delivery with epidermal electrodes remains a challenge due to the need for shape customization, to account for the variance of body morphology among individuals, and the need for conformal contact, to accommodate creviced skin surfaces, intricate curves, and moving bodies. In this study, a conductive and self‐adhesive hydrogel for direct ink writing of wearable electrodes on the skin is presented, utilizing physical cross‐linking mechanisms between bio‐based polymers. With a fast gelation time and a facile fabrication method, the printed hydrogel achieves a 0.40 mm resolution via handheld 3D printers. Compared with silver/silver chloride (Ag/AgCl) coated gel electrode standards, the hydrogel electrode formed in situ achieves a higher signal‐to‐noise ratio by 88%, for the monitoring of forearm muscle biopotential and decreases the required current from 3.5 to 2.25 mA, for the functional electrical stimulation for eye closure. The lowered contact impedance of the hydrogel electrode is attributed to its sol–gel transition in situ on the skin, demonstrating its potential to enable future healthcare applications with improved personalization, efficiency, and comfort. [ABSTRACT FROM AUTHOR]

Of significant interest are three‐dimensional (3D) printed dry electrodes, a departure from traditional wet silver/silver chloride (Ag/AgCl) electrodes. These innovative electrodes not only incorporate 3D printed personalized materials but also eliminate the need for electrolyte gel, which tends to dehydrate over time. Additionally, these electrodes boast unique attributes such as stretchability, deformability, biocompatibility, wearable comfort, and cost‐effective manufacturing. While the advantages of dry electrodes are apparent, their performance optimization encounters challenges related to charge migration, particularly when scaled down to miniaturized dimensions, impacting biosignal detection. This study addresses these challenges by focusing on the development of scalable, stretchable, and highly deformable syringe‐printed dry electrocardiogram (ECG) patches. The approach employs straightforward multi‐material direct‐ink‐writing (DIW) techniques, realizing complete biopatches per print, resulting in a rapid and cost‐effective fabrication process. The achieved printing resolution reaches up to 200 µm, and the conductivity of Ag/AgCl dry electrodes reaches approximately ∼ 5 × 104 S/m. This not only ensures scalability but also expands the applications of metal‐based inks to various soft electronic devices, particularly in low‐resource settings and environments. [ABSTRACT FROM AUTHOR]

Recently electronic tattoo sensors have attracted immense interest for health monitoring mainly due to their higher sensing performance than conventional dry sensors, owing to the ultra-low thickness which results in their conformability to the skin. However, their performance is worse than wet sensors. Further, these electronic tattoo sensors are not durable and reusable when free-standing because of their low thickness and being too delicate. Here, we report a remarkably high-performance freestanding, reusable, ultrathin and ultra-soft electronic tattoo sensor made of parylene-hydrogel double layer system with high water retention over extended periods that can be used for the extended period of 6 months. The hydrogel electronic tattoo (HET) sensors consist of electrically conductive self-adhesive hydrogel with a thickness of 20 µm and Young's modulus of only 31 kPa at 37 °C, allowing for ultra-conformal contact to the skin microscopic features. Our HET sensors are fabricated using a scalable cost-effective method on ordinary tattoo papers and are laminated on the skin like temporary tattoos and were used for electrophysiological signals recording such as electrocardiography (ECG), electromyography (EMG), and skin hydration, temperature sensing. The HET sensors, for the first time, show 234% lower sensor-skin interface impedance (SSII) and significantly lower susceptibility to motion than gold standard medical grade silver/silver chloride wet gel electrodes which are known to have the lowest SSII and susceptibility to motion. Further, the low HET-skin interface impedance leads to a considerably larger signal amplitude and signal-to-noise ratio (SNR) of the electrophysiological signals recorded using HET sensors in comparison with those obtained using gold standard medical grade silver/silver chloride wet gel electrodes. The SNR of some types of electrophysiological signals such as EMG recorded using HET is up to 19 dB higher than gold standard medical grade electrodes due to higher signal amplitude, significantly lower susceptibility of HET to motion and lower motion artifacts. Also, the HET sensor is the first free-standing ultrathin tattoo sensor that can be transferred from the skin to tattoo paper and vice versa many times and the electrophysiological sensing quality remained high during repeated use for over 6 months. [ABSTRACT FROM AUTHOR]

The direct and indirect electrochemical behavior of finasteride was studied using a differential pulse technique coupled with a three-electrode detection system consisting of 2 mm diameter glassy carbon as a working electrode, 2 mm diameter platinum wire as an auxiliary electrode, and silver/silver chloride saturated potassium chloride as reference electrode (Ag/AgCl sat KCl). The finasteride gives a weak reduction peak at -0.68 V. The calibration curve of finasteride was constructed using Briton-Robinson buffer solution (pH = 3), the plot of reduction peak current and concentration gives a linear relationship within the concentration range of 0.999×10-5-19.607×10-5 M, with a correlation coefficient of 0.9903. To increase the sensitivity of the method, an indirect determination of finasteride through its interaction with cupric ion was investigated in acetate buffer solution (pH=2) and followed the decrease in reduction peak current of cupric ion as a result of adding sequence addition of finasteride solution. The calibration curve for finasteride was also constructed for its interaction with cupric ions by measuring the decrease of cupric reduction peak current with the sequence additions of finasteride. The calibration curve was linear within the concentration range of 4.997×10-6-476.191×10-6 M, with a correlation coefficient of 0.9930. The binding constant (K) and the Thermodynamic parameters (ΔG, ΔH, and ΔS) for Cu2+-finasteride interaction were calculated. The suggested method was successfully applied for the determination of finasteride in tablets. [ABSTRACT FROM AUTHOR]

Here, we report an ultrasoft extra long-lasting, reusable hydrogel-based sensor that enables high-quality electrophysiological recording with low-motion artifacts. The developed sensor can be used and stored in an ambient environment for months before being reused. The developed sensor is made of a self-adhesive electrical-conductivity-enhanced ultrasoft hydrogel mounted in an Ecoflex-based frame. The hydrogel's conductivity was enhanced by incorporating polypyrrole (PPy), resulting in a conductivity of 0.25 S m−1. Young's modulus of the sensor is only 12.9 kPa, and it is stretchable up to 190%. The sensor was successfully used for electrocardiography (ECG) and electromyography (EMG). Our results indicate that using the developed hydrogel-based sensor, the signal-to-noise ratio of recorded electrophysiological signals was improved in comparison to that when medical-grade silver/silver chloride (Ag/AgCl) wet gel electrodes were used (33.55 dB in comparison to 22.16 dB). Due to the ultra-softness, high stretchability, and self-adhesion of the developed sensor, it can conform to the skin and, therefore, shows low susceptibility to motion. In addition, the sensor shows no sign of irritation or allergic reaction, which usually occurs after long-term wearing of medical-grade Ag/AgCl wet gel electrodes on the skin. Further, the sensor is fabricated using a low-cost and scalable fabrication process. [ABSTRACT FROM AUTHOR]

Dinitrogen pentoxide (N2O5), the anhydride of nitric acid, was synthesised by Henri E´tienne Sainte-Claire Deville in Paris in 1849 using silver nitrate and chlorine gas. Herein, we revisit, optimise, and modify Deville’s method using photocatalysis to enable a safe, clean, practical, and reproducible alternative for N2O5 synthesis in quantitative yields. Moreover, it is predicted that the modifications can accommodate an industrial scale-up, but the silver chloride generated must be recycled. [ABSTRACT FROM AUTHOR]

Research-oriented experimental teaching has emerged as a prominent focus in higher education’s pedagogical studies. Silver nitrate, a notably costly reagent, poses a dual opportunity when recovered from silvercontaining waste: it mitigates environmental pollution and reduces experimental costs. The experiment requires simple equipment, enabling students to apply their learned knowledge and skills effectively in resolving operational and procedural challenges. This study utilizes the recovery of silver nitrate from silver-containing waste liquid as the experimental project, where students independently devise their experimental strategies. Through the implementation of the scheme, they engage in a research-based learning process, thereby fostering their scientific research acumen. [ABSTRACT FROM AUTHOR]

Although the properties of unsubstituted metal tetrapyrroles in solutions have received attention in numerous work, the physico-chemistry of their thin films remains poorly investigated. In this work, we constructed thin films of unsubstituted cobalt phthalocyanine on the surface of quartz plates and indium tin oxide (ITO) electrodes using the Langmuir-Schaefer (LS) and drop casting techniques. In LS films, CoPc species are involved in strong intermolecular interactions, which result in formation of CoPc nanostructures and prominent changes in the ultraviolet-visible spectrum. Electrochemical reduction of CoPc in LS films at −0.9 V (versus silver chloride electrode) results in formation of Co(I) species. In contrast to the highly reactive nature of Co(I)Pc in solution, these species generated in thin films are relatively resistant to dioxygen due to the dense packing of CoPc units. These findings can further the development of CoPc-based resistive sensors utilizing not only common Co(II), but also Co(I) species, which may possess different sensitivity toward analytes. [ABSTRACT FROM AUTHOR]

The title compound, [Ag2(C19H20N2)4]Cl·0.5C2H4Cl2, can be readily generated by treatment of (1-benzyl-3-(2,4,6-trimethylphenyl)imidazolium chloride with sodium bis(trimethylsilyl)amide followed by silver chloride. The molecular structure of the compound was confirmed using NMR spectroscopy and single-crystal X-ray diffraction analysis. The crystal structure of the title compound at 110 K has monoclinic (P21/c) symmetry. The represented silver compound is of interest with respect to antibacterial properties and the structure displays a series of weak intermolecular hydrogen-bonding interactions with the chloride counter-anion.

Electrochemical (EC) detection is a powerful tool supporting simple, low-cost, and rapid analysis. Although screen printing is commonly used to mass fabricate disposable EC chips, its mask is relatively expensive. In this research, we demonstrated a method for fabricating three-electrode EC chips using 3D printing of relatively high-viscosity paste. The electrodes consisted of two layers, with carbon paste printed over silver/silver chloride paste, and the printed EC chips were baked at 70 °C for 1 h. Engineering challenges such as bulging of the tubing, clogging of the nozzle, dripping, and local accumulation of paste were solved by material selection for the tube and nozzle, and process optimization in 3D printing. The EC chips demonstrated good reversibility in redox reactions through cyclic voltammetry tests, and reliably detected heavy metal ions Pb(II) and Cd(II) in solutions using differential pulse anodic stripping voltammetry measurements. The results indicate that by optimizing the 3D printing of paste, EC chips can be obtained by maskless and flexible 3D printing techniques in lieu of screen printing. [ABSTRACT FROM AUTHOR]

This study explored the remineralization effect of Silver diamine fluoride (SDF) and theobromine on the bond strength, morphology, and elemental composition of carious dentin in primary teeth in vitro. Thirty-five extracted primary molars were sectioned, embedded in resin blocks, with 2 mm of the occlusal surface removed to expose dentin. For the microtensile bond strength (μTBS) test, 32 specimens were assigned to four groups: untreated dentin, deionized water, SDF, and theobromine, with pH cycling for the latter three. The Single Bond Universal adhesive was applied, and a composite rod was cast. Longitudinal sections were cut to produce 1×1 mm² beams and μTBS was measured. Three additional teeth were sectioned to produce 2 mm dentin discs, which were allocated into the four groups for scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) examination. The μTBS was significantly restored in the theobromine group, reaching a level comparable to untreated dentin group. SEM and EDS revealed that theobromine induced calcium and phosphate crystals formation, while SDF caused silver chloride salt precipitation. Thus, theobromine may enhance remineralization and bond strength, while SDF may reduce bond strength due to silver chloride precipitates. [ABSTRACT FROM AUTHOR]

A casket held at Bateman's, Rudyard and Caroline Kipling's home in Sussex—now a National Trust property—was recently recognised as a barniz brillante work. Objects made of barniz brillante, a technique featuring the Indigenous American material called mopa mopa, are relatively rare and have only sparingly been studied using scientific analysis techniques. A collaboration between the National Trust and the Victoria and Albert Museum has produced scientific evidence which will be invaluable in the study and the understanding of this type of object. The scientific analysis of the casket was conducted exclusively in a non-destructive and non-invasive manner, to preserve the integrity of the object which is in very good condition. The Bateman's casket is characterised by a dark underdrawing, made with a material which is transparent in the infrared region of the electromagnetic spectrum. Most of the areas decorated with silver leaf have tarnished due to the formation of what is likely to be silver chloride. This study represents a significant step towards the comparative scientific study of barniz brillante objects in other collections, which in turn will make it possible to suggest a timeline for their manufacture, and even identify workshops. [ABSTRACT FROM AUTHOR]

Silver telluride represents one of the most important refractory silver mineral phases and requires the development of alternative processing routes. This work presents a detailed analysis of the effect of sodium and calcium hypochlorite species, HNO3, HCl, H2SO4 and pH on the kinetics and efficiency of silver telluride dissolution. The understanding of the reaction mechanism was complemented with the use of thermodynamic diagrams and characterization of the solid residues by the X-ray diffraction and SEM-EDS techniques. The results revealed that the presence of Ca(ClO)2 and H2SO4 promotes the secondary and massive precipitation of calcium sulfate. A comparison of the oxidative systems containing Ca(ClO)2 and NaClO showed that the solutions containing NaClO are more efficient and selective. The decrease in pH favors the tellurium dissolution due to an increase in the in-situ concentration of chlorine oxidizing species; the silver is transformed into silver chloride solid species on the surface of unreacted silver telluride. Thermodynamic and experimental studies revealed that silver chloride layer and the continuous consumption of hypochlorous acid promote the passivation of the system. The characterization of the solid residues evidenced that the type of acid contained in the systems modifies the morphology of the silver chloride layer. Finally, the surface characterization showed that passivation due to the formation of compact layer of silver chloride can be modified using a hypochlorite system containing nitric acid; this is due to a synergistic effect of nitrate and hypochlorite species on the kinetics of silver telluride dissolution. This effect is also discussed from a mechanistic viewpoint. Silver telluride is oxidized in different hypochlorite acid systems. Passivating compact layer of AgCl are obtained in H2SO4 and HCl. The HClO-HNO3 system accelerates the silver telluride dissolution. The presence of HNO3 promotes the formation of porous AgCl. 86% of Te is dissolved from silver telluride at pH 1 [ABSTRACT FROM AUTHOR]

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Modern technology's development is also towards using microorganisms as micro-factories of biomaterials with unique properties and combining the original properties of biosilica extracted from diatoms (microalgae) together with immobilised silver and cerium in nanoparticle forms allowed to obtain a modern composite material with antibacterial activity. The synthesised composites containing heteroepitaxially growing Ag/AgCl/CeO2 complex nanoparticles were studied using different types of instrumental analysis. SEM-EDX and XRD analysis allowed the qualitative and quantitative determination of the elements present and their forms in the composites. TEM permitted analysis of information about the created nanoparticles shape, size and structure specificity. The possible mechanism of nanoparticle formation was suggested. Antibacterial properties of synthesised composites were characterised using a minimum inhibitory concentration test on six selected bacterial strains. Diatomaceous biosilica containing heteroepitaxially growing silver chloride, metallic silver, and cerium (IV) oxide nanoparticles have been prepared for the first time. The proposed method for synthesising composites did not use toxic reagents, making it environmentally friendly. [ABSTRACT FROM AUTHOR]

Reliable room temperature carbon monoxide (CO) detection remains a key challenge constrain existing gas sensor technologies. Polyaniline (PANI)-based chemiresistors show promise but exhibit deficiencies including slow response/recovery and limited sensitivity. This work develops a silver chloride-functionalized protonated PANI integrated with graphene oxide (AgCl@PA-PANI/GO) nanocomposite sensor to address these limitations. The synergistic combination of PA-PANI, GO, and AgCl nanoparticles creates a tailored architecture to enable rapid and sensitive CO chemiresistive transduction at room temperature. Fabrication of flexible sensors was followed by materials characterization verifying successful composite synthesis. Gas sensing assessments demonstrated remarkable performance improvements including 50/39 s response/recovery times and 19.5% sensitivity at 130 ppm CO along with stability over multiple cycles. Comparative analysis verified that incorporating AgCl with PA-PANI/GO amplified the sensitivity by 4X and reduced response/recovery times by over 35% compared to unmodified PA-PANI/GO. This establishes a new materials-by-design approach to overcome existing limitations through rational nanocomposite engineering. [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]

Excellent conductivity makes silver (Ag) an attractive electrode and current collector material for a variety of devices, also promising faster soft actuators. However, high reactivity challenges the use of Ag in electrochemical systems, as dendritic growth can create undesired conduction pathways and short‐circuit the oppositely polarized electrodes. The challenge of rapid Ag electrochemical migration is addressed using a mixed mixed‐room temperature ionic liquid (RTIL) system (l‐ethyl‐3‐methylimidazolium bis‐(trifluoromethylsulfonyl)‐imide and trihexyl(tetradecyl)phosphonium chloride) that prevents short‐circuiting by engaging the produced Ag+ ions with Cl− anions. The stability of the system is demonstrated on an ionic actuator using Ag–silver chloride (AgCl) electrodes and a mixed‐RTIL electrolyte. The work demonstrates fast (in 5 s) transfer of a large (0.2 C cm−2) charge to high‐specific‐surface‐area carbon without observable dendritic growth in cycling and good electromechanical performance: 4° s−1 deflection rate at 0.8 V s−1 scan rate. Simple spray‐deposition of the Ag–AgCl electrodes promises scalable and cost‐effective fabrication. The combination of high stability and vast charge capacity encourages the engagement of Ag‐based electrodes for many electrochemical applications involving organic electrolytes also beyond robotics. [ABSTRACT FROM AUTHOR]

Purpose: Electromyography (EMG) is a technique dealing with the recording and analysis of myoelectric signals formed by physiological variations in the muscle fiber membrane. The voltage potential of surface myoelectrical signals (sEMG) varies over time and depends on the characteristics of the individual subject. One of the main drawbacks of sEMG analysis is that the given acquisition conditions strongly determine the amplitude of the signal. The analysis of sEMG requires appropriate preprocessing, including proper filtering and artifact removal. Moreover, the sEMG data must be converted to a scale standardized for all measurements. This research aimed both to propose a method of sEMG processing to eliminate the occurring disturbances, in particular impulsive artifacts, and to determine the level of muscle excitation based on normalized sEMG. The analysis of muscle excitation level can be applied to assess muscle activity during physical activity. Design/methodology/approach: The proposed algorithm uses set of digital filters, probabilistic distribution and the decomposition of the sEMG signal to attenuate artifacts. Variance analysis of the sEMG derivative is used to determine muscle excitation. The sEMG signals were acquired with the VICON system with the sampling frequency set at 1000 Hz, and processed in MATLAB. During sEMG recordings, standard silver/silver chloride (Ag/AgCl) surface electrodes were used. Findings: The suggested technique was validated using sEMG recorded for eight persons during deep squat. Normalized excitation was determined for the left and right muscles, the rectus femoris, the vastus medialis, and the biceps femoris. Obtained outcomes indicate a possibility to assess the correctness of muscles condition. Originality/value: The combination of the proposed filter and the analysis variance-based thresholding method can effectively eliminate impulse artifacts within the surface myoelectrical signals. [ABSTRACT FROM AUTHOR]

This work presents a continuous roll-to-roll electrochemical coating system for producing silver/silver chloride (Ag/AgCl)-coated yarns, and their application in e-textile electrodes for biosignal monitoring. Ag/AgCl is one of the most preferred electrode materials as an interface between the conductive backbone of an electrode and skin. E-textile Ag/AgCl-coated multi-filament nylon yarns offer stable, flexible, and breathable alternatives to standard rigid or flexible film-based Ag/AgCl electrodes. The developed system allows for highly controlled process parameters to achieve stable and uniform AgCl film deposition on Ag-coated nylon yarns. The electrical, electrochemical properties, and morphology of the coated yarns were characterized. Dry electrodes were fabricated and could measure electrocardiogram (ECG) signals with comparable performance to standard gel electrodes. Ag/AgCl e-textile electrodes demonstrated high stability, with low average polarization potential (1.22 mV/min) compared with Ag-coated electrodes (3.79 mV/min), low impedance (below 2 MΩ, 0.1–150 Hz), and are excellent candidates for heart rate detection and monitoring. [ABSTRACT FROM AUTHOR]

There is an increasing interest in long-term electrocardiography (ECG) monitoring in veterinary clinical practice. ECG is the most essential physiological signal in diagnosing and managing heart diseases both in humans and animals. Electrodes are the main components that affect the quality of the acquired signal. This study focuses on the development of silver-coated textile electrodes for veterinary ECG testing (particularly for dogs). Silver printed polyester, embroidered, and silver-plated conductive hook textile electrodes were used for ECG measurement in dogs. This is an important validation for the use of textile ECG sensors in combination with hairy skin. ECG signals were collected while the animal was in a static position and walking on a smooth surface. The ECG signals collected from the dog using the silver printed polyester and embroidered textile electrodes with slight skin preparation have identifiable P, QRS, and T waveforms and were comparable with signals from standard silver/silver chloride (Ag/AgCl) electrodes. Results revealed that these textile electrodes can be used for ECG monitoring in a dog to avoid associated problems with commercially used crocodile clamps and standard Ag/AgCl electrodes. The hook electrodes show promising results when placed on the hairy regions of a dog without any skin preparation. [ABSTRACT FROM AUTHOR]

IntroductionSilver Diammine Fluoride (SDF) is a clinically used topical agent to arrest dental caries. However, the kinetics of its chemical interactions with hydroxyapatite (HA), the principal inorganic component of dental enamel, are not known. The aim was to characterize the step-wise chemical interactions between SDF and HA powder during the clinically important process of remineralization.MethodsTwo grams of HA powder were immersed in 10 ml acetic acid pH = 4.0 for 2 h to mimic carious demineralization. The powder was then washed and dried for 24 h and mixed with 1.5 ml SDF (Riva Star) for 1 min. The treated powder was then air-dried for 3 min, and 0.2 g was removed and stored in individual tubes each containing 10 ml remineralizing solution. Powder was taken from each tube at various times of exposure to remineralization solution (0 min, 10 min, 2 h, 4 h, 8 h, 24 h, and 10 days), and characterized using Magic Angle Spinning-Nuclear Magnetic Resonance (MAS-NMR) spectroscopy.Results and discussion19F MAS-NMR spectra showed that calcium fluoride (CaF2) started to form almost immediately after HA was in contact with SDF. After 24 h, the peak shifted to −104.5 ppm suggesting that fluoride substituted hydroxyapatite (FSHA) was formed with time at the expense of CaF2. The 31P MAS-NMR spectra showed a single peak at 2.7 ppm at all time points showing that the only phosphate species present was crystalline apatite. The 35Cl MAS-NMR spectra showed formation of silver chloride (AgCl) at 24 h. It was observed that after the scan, the whitish HA powder changed to black color. In conclusion, this time sequence study showed that under remineralization conditions, SDF initially reacted with HA to form CaF2 which is then transformed to FSHA over time. In the presence of chloride, AgCl is formed which is subsequently photo-reduced to black metallic silver.

The prevalence of numerous infectious diseases has emerged as a grave concern within the realm of healthcare. Currently, the issue of antibiotic resistance is compelling scientists to explore novel treatment approaches. To combat these infectious diseases, various treatment methods have been developed, harnessing cutting-edge disinfecting nanomaterials. Among the range of metallic nanoparticles employed in medicine, silver nanoparticles (AgNPs) stand out as both highly popular and well-suited for the task. They find extensive utility in cancer diagnosis and therapies and as effective antibacterial agents. The interaction between silver and bacterial cells induces significant structural and morphological alterations, ultimately leading to cell demise. In this study, nanoparticles based on silver and bambusuril[6] (BU[6]) were developed for the first time. These NPs can be used for different biomedical purposes. A simple, single-step, and effective synthesis method was employed to produce bambusuril[6]-protected silver chloride nanoparticles (BU[6]-Ag/AgCl NPs) through the complexation of BU[6] with silver nitrate. The NPs were characterized using X-ray phase analysis (XPS), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). When the SEM images were examined, it was seen that the synthesized BU[6]-Ag/AgCl NPs were distributed with homogeneous sizes, and the synthesized NPs were mostly spherical and cubic. The EDS spectra of BU[6]-Ag/AgCl NPs demonstrated the presence of Ag, Cl, and all expected elements. BU[6]-Ag/AgCl NPs showed high antibacterial activity against both E. coli and S. aureus bacteria. [ABSTRACT FROM AUTHOR]

This work presents the synthesis of polymer resins with heterocyclic functional groups, that is, N-(3-aminopropyl)-2-pipecoline, N-(3-aminopropyl)-2-pyrrolidinone, and trans-1,4-diaminocyclohexane for the recovery of Ag(I) from chloride solutions. The modification yield was 69.2, 74.6 and 88.3%, respectively. The best Ag(I) sorption was achieved from synthetic and real chloride solutions in the case of trans-1,4-diaminocyclohexane resin (sorption was 26.8 and 21.5 mg/g, respectively). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The maximum sorption capacity of Ag(I) is 105.4, 117.8 and 130.7 mg Ag(I)/g for N-(3-aminopropyl)-2-pipecoline resin, N-(3-aminopropyl)-2-pyrrolidinone resin and trans-1,4-diaminocyclohexane resin, respectively. The trans-1,4-diaminocyclohexane modified resin was very selective towards Ag(I) compared to Cu(II), Pb(II), and Zn(II) from the real chloride leaching solution. The N-(3-aminopropyl)-2-pipecoline and N-(3-aminopropyl)-2-pyrrolidinone resins showed high preferences for Ag(I) over Pb(II) in real solution. These results indicated that the polymers can be applied in the recovery of Ag(I). [ABSTRACT FROM AUTHOR]

An ultrasensitive dual-signal ratiometric electrochemical sensor was developed for creatinine detection utilizing silver nanoparticles (Ag) with intrinsic self-calibration afforded by iron-nickel bimetallic Prussian blue (FeNiPBA) analogues. The Ag@FeNiPBA exhibits two redox signals corresponding to the Ag+/Ag and Fe3+/Fe2+ systems. Adding chloride (Cl−) solution increases the anodic current of the Ag/Ag system significantly due to the formation of silver chloride through solid-state electrochemistry. While the anodic current of the Ag/Ag system decreases in the presence of creatinine due to the competitive reaction, the Fe/Fe system's anodic current remains the same, which enables a ratiometric response. Under optimized conditions, the response ratio (IAg/IFe) decreases while the creatinine concentration increases linearly between 0.015 and 140 μM, with 0.004 μM as a good detection limit (S/N = 3). These results demonstrate superior performance over previously reported methods for electrochemical creatinine determination. The high sensitivity arises from the signal amplification of the Ag/AgCl solid-state electrochemistry, while the selectivity originates from the specific interaction between Ag+ and creatinine. The Ag@FeNiPBA hybrid can quantify creatinine in real samples with good recoveries. This work opens up new opportunities for applying dual-signal nanostructures to develop electrochemical sensors for (bio)molecule detection. [ABSTRACT FROM AUTHOR]

Electrocardiogram (ECG) electrodes are important sensors for detecting heart disease whose performance determines the validity and accuracy of the collected original ECG signals. Due to the large drawbacks (e.g., allergy, shelf life) of traditional commercial gel electrodes, textile electrodes receive widespread attention for their excellent comfortability and breathability. This work demonstrated a dry electrode for ECG monitoring fabricated by screen printing silver/silver chloride (Ag/AgCl) conductive ink on ordinary polyester fabric. The results show that the screen-printed textile electrodes have good and stable electrical and electrochemical properties and excellent ECG signal acquisition performance. Furthermore, the resistance of the screen-printed textile electrode is maintained within 0.5 Ω/cm after 5000 bending cycles or 20 washing and drying cycles, exhibiting excellent flexibility and durability. This research provides favorable support for the design and preparation of flexible and wearable electrophysiological sensing platforms. [ABSTRACT FROM AUTHOR]

A new and simple fabrication method of the highly sensitive Ag/AgCl chloride sensor for the real-time monitoring of the water quality was reported. The working electrode was prepared by hot-dipping with AgCl+Ag2S melt after the electrochlorization of Ag wire. The potentiometric response to chloride in environmental sample was systematically studied. The results show a good linear relationship between the potential of the sensor and the logarithm of chloride concentration (from 5*10−4 mol·L−1 to 1 mol·L−1). The maximum deviation from the mean open circuit potential of 9 sensors in the same sample was very low as 3 mV. The developed sensor has a good long-time ability in different abrasive fluids such as tap water, irrigation water and sea water due to the high mechanical and chemical robustness of the electrode surface. The small differences in lifetime in different samples are attributed to the change of abradability and chloride level of samples. Using these sensors, a Cl− monitoring system for the local saline area can be easily constructed. And this system will be a valuable tool in the fields of hydrology, agriculture and environmental science. [ABSTRACT FROM AUTHOR]

We herein present a simple, fast, low-temperature, post-glass melting fabrication protocol in which a photochromic silver cation based modified zone is incorporated within silver metaphosphate glass (AgPO3). The selection of AgPO3 glass is mainly based on its relative “soft” nature (Tg = 192 °C) that enables the integration of silver cations from the surface deposited AgCl layer, while being transparent in most of the visible range, and therefore suitable for smart photochromic window applications. The suggested synthesis procedure permits the controlled formation of a silver cation modified layer within the host glass matrix, while the characteristics of the layer itself can be adjusted correspondingly. Our findings reveal a direct relationship between the developed composite AgCl–AgPO3 glass photochromic response and the morphological features of the integrated layer, i.e., thickness and position. More importantly, the photochromic response time with various UV irradiation doses is also studied, where remarkable response times of several seconds are obtained. Processes and efforts to further enhance the photochromic performance by utilizing the presence of silver nanoparticles within the glass matrix are also presented and discussed.

An advanced three-dimensional printing process for producing the silver clusters/ Silver(I) chloride/titanium dioxide-coupled photocatalyst was developed and tested for its stability and degradability in relation to azo dye (Orange II) and bacteria (Escherichia coli). The titanium dioxide structure is produced through fused filament fabrication (FFF) with filaments of thermoplastic material, which is composed of titanium dioxide anatase nanoparticles, high density polyethylene (HDPE), stearic acid, wax, and plasticizer. The TiO2 structure is then solvent degreased, thermal degreased, and sintered to become a fundamental structure to couple the AgCl particles through an ion exchange process. Following the photoreduction of UV radiation, a silver clusters/Silver(I) chloride/titanium dioxide-coupled photocatalyst is formed. In our experiments, the degradation of Orange II dye and E. coli was performed under visible and ultraviolet light irradiation. The degradation kinetics of Orange II dye was a first-order reaction, with the degradability (94%) persisting for five cycles. The sterilization of E. coli was accomplished within 120 min, and the degradation kinetics were characteristic of a hyperbolic reaction. The photocatalytic module prepared through FFF not only exhibited the ability to degrade contaminants in water but also exhibited durability and reliability after repeated use. [ABSTRACT FROM AUTHOR]

Continuous monitoring of arterial blood pressure is clinically important for diagnosing and managing cardiovascular diseases. Soft electronic devices with skin‐like properties show promise in various applications, including the human‐machine interface, the Internet of Things, and health monitoring. Herein, the use of add‐on soft electronic interfaces addresses the connection challenges between soft electrodes and rigid data acquisition circuitry for bioimpedance monitoring of cardiac signals, including heart rate and cuffless blood pressure is reported. Nanocomposite films in add‐on electrodes provide robust electrical and mechanical contact with the skin and the rigid circuitry. Bioimpedance sensors composed of add‐on electrodes offer continuous blood pressure monitoring with high accuracy. Specifically, the bioimpedance collected with add‐on nanocomposite electrodes shows a signal‐to‐noise ratio of 37.0 dB, higher than the ratio of 25.9 dB obtained with standard silver/silver chloride (Ag/AgCl) gel electrodes. Although the sample set is low, the continuously measured systolic and diastolic blood pressure offer accuracy of −2.0 ± 6.3 mmHg and −4.3 ± 3.9 mmHg, respectively, confirming the grade A performance based on the IEEE standard. These results show promise in bioimpedance measurements with add‐on soft electrodes for cuffless blood pressure monitoring. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is a global problem and bacterial biofilms contribute to its development. In this context, this study aimed to perform the synthesis and characterization of seven materials based on silica mesoporous nanoparticles functionalized with three types of fluoroquinolones, along with Cu2+ or Ag+ species to evaluate the antibacterial properties against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, including clinical and multi-drug-resistant strains of S. aureus and P. aeruginosa. In addition, in order to obtain an effective material to promote wound healing, a well-known proliferative agent, phenytoin sodium, was adsorbed onto one of the silver-functionalized materials. Furthermore, biofilm studies and the generation of reactive oxygen species (ROS) were also carried out to determine the antibacterial potential of the synthesized materials. In this sense, the Cu2+ materials showed antibacterial activity against S. aureus and E. coli, potentially due to increased ROS generation (up to 3 times), whereas the Ag+ materials exhibited a broader spectrum of activity, even inhibiting clinical strains of MRSA and P. aeruginosa. In particular, the Ag+ material with phenytoin sodium showed the ability to reduce biofilm development by up to 55% and inhibit bacterial growth in a "wound-like medium" by up to 89.33%. [ABSTRACT FROM AUTHOR]

In this work, an environmentally friendly and cost-effective one-step electrodeposition technique was used to synthesize Ag-doped CuSbS2 (CAS) thin films to optimize the photoelectrochemical (PEC) properties. An experimental study was performed on undoped and doped samples by tuning the concentrations of silver chloride (AgCl), as Ag doped precursor. The impact of Ag-coating on structural, physical properties, and PEC performances of electrodeposited CAS thin films have been thoroughly characterized using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy (UV–Vis) and electrochemical impedance spectroscopy (EIS). XPS measurements corroborated the incorporation of Ag ions into the host CAS photocathodes. Under optimized Ag-coating degree (10 at.%Cu) (ACAS10), the photocurrent density of the built photocathode generates a maximum photocurrent density up to ca. − 0.52 mA cm−2 at 0 V vs. RHE (reversible hydrogen electrode), which is approximately 10 times higher than the undoped one. In addition, a considerable anodically shift in the onset potential could reach 0.48 V vs. RHE. Internal photon-to-current conversion efficiencies (IPCEs) measurements showed the spectral distribution of the photocurrent generation revealing a broad response of the CAS-based photocathode. The stability tests were investigated for all the photoelectrodes at 0 V vs. RHE and revealed that the photocurrent retention could be obtained under chopped illumination for 10 min. The flat band potential (Vfb = 0.46 V vs. RHE) and acceptor coating density NA = 1.2 1018 cm−3 were estimated by Mott Schottky measurements. The Nyquist plot displays only one well-shaped semicircular arc, which approves the good homogeneity of all found CAS photocathodes. We believe that the optimized Ag-coating process of the CAS photocathode is an effective and efficient tuning of the physical properties resulting in boosted PEC properties for generating solar fuels from water. [ABSTRACT FROM AUTHOR]

Polyaniline-silver chloride nanocomposites were prepared by in-situ chemical oxidation polymerization with polyaniline with good conductivity as substrate and photosensitive semiconductor material silver chloride as initiator, and their electrical and optical properties were systematically studied. The morphology, structure, optical properties, and conductivity of polyaniline monomer and polyaniline or silver chloride nanocomposites were characterized and compared by scanning the electron microscope, quaternary probe conductivity tester, and simulating sunlight illumination. The results show that polyaniline silver chloride nanocomposites have good thermal stability; nano-silver chloride particles are uniformly dispersed in polyaniline; the doping of silver chloride will have a positive effect on the conductivity of the composites. At the same time, silver chloride with surface metal plasma oscillation effect is doped in the composite material, which makes the composite material have excellent light absorption and catalytic performance. [ABSTRACT FROM AUTHOR]

Here, I fill large 1.7 nm diameter single-walled carbon nanotubes (SWCNTs) with silver chloride (AgCl). I present photoemission insights into the filling of SWCNTs. C1s X-ray photoelectron spectroscopy (XPS) reveals the p-doping of SWCNTs. The Raman spectroscopy data are complementary to the XPS data, and they confirm the strong doping effect of encapsulated silver chloride on SWCNTs. [ABSTRACT FROM AUTHOR]

In situ NMR spectroelectrochemistry is extremely powerful in studying redox reactions in real time and identifying unstable reaction intermediates. In this paper, in situ polymerization synthesis of ultrathin graphdiyne (GDY) nanosheets was realized on the surface of copper nanoflower/copper foam (nano−Cu/Cuf)-based electrode with hexakisbenzene monomers and pyridine. Palladium (Pd) nanoparticles were further deposited onto the GDY nanosheets by the constant potential method. By using this GDY composite as electrode material, a new NMR-electrochemical cell was designed for in situ NMR spectroelectrochemistry measurement. The three-electrode electrochemical system consists of a Pd/GDY/nano−Cu/Cuf electrode as the working electrode, a platinum wire as the counter electrode, and a silver/silver chloride (Ag/AgCl) wire as a quasi-reference electrode, which can be dipped into a specially constructed sample tube and adapted for convenient operation in any commercial high-field, variable-temperature FT NMR spectrometer. The application of this NMR-electrochemical cell is illustrated by monitoring the progressive oxidation of hydroquinone to benzoquinone by controlled-potential electrolysis in aqueous solution. [ABSTRACT FROM AUTHOR]

Identifying a suitable textile electrode that would be durable and assist in recording high-quality bio-signal quality is crucial in the production of medical devices. Therefore, this study is aimed at comparing the time domain characteristics of silver-plated-polyamide-embroidered cotton (SPEC), copper-nickel-plated polyester (CNP), and stainless-steel-fabric (SSF) dry textile electromyography (EMG) electrodes through principal component analysis (PCA). The standard silver/silver chloride (Ag/AgCl) gel electrode was considered as the reference for all the test textile electrodes mentioned above. The EMG signal was measured by activation of the bicep and tibialis anterior muscles, and the time domain features such as root mean square (RMS) voltage, average rectified value (ARV) voltage, signal to noise ratio (SNR), kurtosis, and skewness were extracted from the EMG signal. The SSF electrode outperformed CNP and SPEC electrodes. Each textile electrode exhibited signal-to-noise ratio (SNR) values comparable to that of the standard electrode. The SNR values were 24.38 dB, 17.72 dB, 15.55 dB, and 13.30 dB for Ag/AgCl, SSF, CNP and SPEC electrodes, respectively. The performance of all the conductive textile electrodes was comparable to that of Ag/AgCl. However, the gel electrode required skin preparation and exhibited short-term stability, whereas, textile electrode materials were long-lasting and could be used for biological signal monitoring at home without the assistance of medical professionals. [ABSTRACT FROM AUTHOR]

Lectins are carbohydrate‐binding proteins belonging to the Leguminosae family. In this family stand out proteins extracted from species belonging to Diocleinae subtribe, which includes, for example, the seed lectin from Dioclea violacea (DVL) and the jack bean lectin Concanavalin A (ConA). Here, we report the photosynthesis of silver/silver chloride nanoparticles (NPs) assisted by ConA and DVL. The syntheses were simple processes using a green‐chemistry approach. Under electron microscopy, NPs heterogeneous in size, nearly spherical and covered by a thin lectin corona, were observed. Both NPs assisted by lectins were capable to cause strong rabbit erythrocytes agglutination with the same titers of hemagglutinating activities. These results indicate that both lectins maintained their biological activities even after association with the NPs and therefore are able to interact with biological membrane carbohydrates. However, for rabbit erythrocytes treated with proteolytic enzymes were observed different titers of hemagglutinating activities, suggesting differences in the spatial arrangement of the lectins on the surface of the NPs. This study provides evidences that these hybrid lectin‐coated silver/silver chloride NPs can be used for selective recognition and interaction with membrane carbohydrates and others biotechnological applications. [ABSTRACT FROM AUTHOR]

Commercial silver/silver chloride (Ag/AgCl) reference electrodes are some of the most commonly used reference electrodes, but they suffer from a number of issues due to their porous frits. Such issues include difficulty miniaturizing, silver and chloride ion leakage, charge screening effects at low ionic strength, frit drying if left unattended in air, and incompatibility with organic solvents. To solve these issues, we recently designed a reference electrode that is leakless in principle by replacing the porous frit with a sealed, conductive wire, where the ends of the wire are exposed to the reference electrode solution and the working electrode solution. We hypothesized that the reference electrode operated like a closed, bipolar electrochemical cell, and we termed the name bipolar reference electrode (BPRE). Here, we provide evidence that the BPRE can either act as a reference electrode by operating through an ion transfer mechanism via leakage through the imperfect seal, or it can act as a highly stable quasi-reference electrode through a bipolar electron transfer mechanism (BPQRE). Finally, we demonstrate the effectiveness of the BPRE in other types of common electrochemical studies, including chronoamperometry, linear sweep voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Aqueous extract of Neolamarchia cadamba leaves were used in the synthesis of silver/silver chloride nanoparticles (Ag/AgCl NPs). Further they were separated based on their using step-wise centrifugation approach at 09,000, 12,000, and 15,000 rpm. Thus obtained NPs were characterized for their physicochemical features. NPs showed maximum absorbance at 455 nm, 415 nm, and 402 nm. All the NPs were found to be crystalline in nature with average crystallite size (nm) of 58.31, 23.43, and 09.56. Particle size distribution (nm) of NPs was observed to 435.43, 276.75, and 105.49, Surface charge (-mV) of NPs was observed to be 14.59, 23.90, and 32.17. Ag/AgCl NPs-rpm@15,000 showed antibacterial activity against Escherichia coli, coagulase-negative Staphylococci, and Staphylococcus aureus with zone of inhibition (mm) of 16.65, 13.69, and 14.02 at 50 µg per well, respectively. Ag/AgCl NPs-rpm@15,000 showed excellent catalytic activity in degradation of methyl red, methylene blue, rhodamine-B, and methyl orange dyes in the presence of sodium borohydride under 4, 6, 5, and 4 min with pseudo-first order rate constant (min−1) of 0.981 (96.4%), 0.666 (97.1%), 0.905 (98.1%), and 1.032 (96.6%), respectively. Furthermore, Ag/AgCl NPs-rpm@15,000 showed good catalytic efficiency even under different dye combinations. Total combination was degraded under 18 min. [ABSTRACT FROM AUTHOR]

In this paper, Ag contained in the lead-silver slag was recovered during the melt-vaporization process. The existing Ag state in the soot was analyzed, the influence of the reaction temperature, the carbon ratio, and the reaction time on the removal rate of the silver was investigated, and the process conditions were optimized using reaction surface methodology. Silver chloride, silver metal, silver sulfide, silver oxide, and silver sulfate are the main silver phases in lead-silver slag, of which silver chloride and silver sulfide are the main phases. The silver oxide (Ag2O) and the silver chloride (AgCl) in the leadsilver slag volatilize to soot, the silver sulfide (Ag2S) is oxidized by oxygen to silver sulfate (Ag2SO4), and elemental silver volatilizes with Pb and Zn to form alloys. The silver is ultimately present as Ag, AgCl, Ag2O and Ag2SO4 in the soot. The removal rate of the silver gradually increases with increasing reaction temperature and tends to remain stable at 1300°C. With a gradual increase in the carbon content, the removal rate of silver first increases and then decreases. The highest value is 80.12 wt% when the carbon content is 16.30 wt%. As the holding time increases, the silver removal rate gradually increases and then stabilizes at 79.97 wt% even at a holding time of 150 minutes. The optimum process conditions for silver removal are a reaction temperature of 1340°C, a carbon content of 16.10 wt%, and a holding time of 165 minutes. The average removal rate of silver under these conditions is 80.42 wt%. The research in this article provides a theoretical basis for the removal and utilization of silver from lead and silver residues. [ABSTRACT FROM AUTHOR]

In this study, we present a novel approach for the preparation of a highly ordered interconnected three-dimensional (3D) porous network structure of a silver atomic cluster (Ag@)/silver chloride photocatalyst using in situ precipitation 3D printing technique). The as-prepared photocatalyst structure exhibited high porosity and was tested for photocatalytic dye degradation and sterilization of Escherichia coli under visible and ultraviolet light irradiation. The results showed that the photocatalyst structure demonstrated strong degradation efficiency towards aqueous solutions of Orange II azo dye and methylene blue dye, and the kinetic properties followed a pseudo-first-order kinetics. The photocatalyst structure also exhibited efficient sterilization of E. coli, and the kinetics followed a pseudo-first-order and hyperbolic kinetics. Furthermore, after five cycles of dye degradation, the photocatalyst structure maintained high degradation rates of approximately 89.8% and 88.2% for Orange II azo and methylene blue dyes, respectively, indicating excellent durability and reliability of the prepared photocatalyst structure. [ABSTRACT FROM AUTHOR]

3D printed on‐skin electrodes are of notable interest because, unlike traditional wet silver/silver chloride (Ag/AgCl) on‐skin electrodes, they can be personalized and 3D printed using a variety of materials with distinct properties such as stretchability, conformal interfaces with skin, biocompatibility, wearable comfort, and, finally, low‐cost manufacturing. Dry on‐skin electrodes, in particular, have the additional advantage of replacing electrolyte gel, which dehydrates and coagulates with prolonged use. However, issues arise in performance optimization with the recently discovered dry materials. These challenges become even more critical when the on‐skin electrodes are scaled down to a miniaturized size, making the detection of various biosignals while keeping mechanical resilience under several conditions crucial. This review paper aims to provide researchers interested in the 3D printing and manufacturing field for healthcare applications, specifically dry electrophysiological (EP) on‐skin electrodes and biosignal sensing methodologies, with a reference guide about the various state‐of‐the‐art 3D printing techniques and materials that have been developed with a focus on the main applications of EP electrodes, such as an electrocardiogram, electrooculogram, electromyogram, and electroencephalogram. [ABSTRACT FROM AUTHOR]

In this paper, we evaluated the impedance of textile electrodes for electroencephalography measurements. We compared the commercially available standard dry silver/silver chloride dry electrodes, copper-based, and silver-based textile electrodes by measuring impedance on the skin. First, on dry skin, the impedance range of the electrodes was 93–350 kΩ at 0 min; after 60 min, the range was 20–56 kΩ. The commercial electrode showed the lowest impedance of 20 kΩ, and the silver-based textile electrode showed the highest impedance of 56 kΩ in dry skin conditions after 60 min. When tap water was applied as an electrolyte, the impedance range was 13–15 kΩ at 0 min; after 60 min, the range was 17–22 kΩ for all three types of electrodes. In this case, the copper-based textile electrode showed the lowest impedance of 17 kΩ and the commercial electrode showed the highest impedance of 22 kΩ after 60 min. When saline water was applied as an electrolyte, at 0 min, the impedance range was 8–11 kΩ; after 60 min, the range became 11–12 kΩ for all three types of electrodes. Thus, all electrodes showed similar results. It was concluded that the copper-based textile electrodes were more suitable than the silver-based textile electrodes and comparable to commercial electrodes regarding impedance in all three skin conditions. [ABSTRACT FROM AUTHOR]

In recent years, the biological synthesis of silver nanoparticles has captured researchers' attention due to their unique chemical, physical and biological properties. In this study, we report an efficient, nonhazardous, and eco-friendly method for the production of antibacterial silver/silver chloride nanoparticles utilizing the leaf extract of Stachys emodi. The synthesis of se-Ag/AgClNPs was confirmed using UV-visible spectroscopy, DPPH free radical scavenging activity, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). An intense peak absorbance was observed at 437 nm from the UV-visible analysis. The Stachys emodi extract showed the highest DPPH scavenging activity (89.4%). FTIR analysis detected various bands that indicated the presence of important functional groups. The SEM morphological study revealed spherical-shaped nanoparticles having a size ranging from 20 to 70 nm. The XRD pattern showed the formation of a spherical crystal of NPs. The antibacterial activity performed against Erwinia carotovora showed the maximum inhibition by centrifuged silver nanoparticles alone (se-Ag/AgClNPs) and in combination with leaf extract (se-Ag/AgClNPs + LE) and leaf extract (LE) of 98%, 93%, and 62% respectively. These findings suggested that biosynthesized NPs can be used to control plant pathogens effectively. [ABSTRACT FROM AUTHOR]

In this study, a low-cost method was used to make an Ag2CO3/AgCl/Cu2O heterostructure from a plant extract of Cissus rhombifolia leaves and a lot of sodium carbonate and chloride from drinking water. X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX) measurements confirm the presence of chlorides and carbonates in the as-prepared sample. The optical analysis outcomes show a high absorption capacity in the visible range with an optical energy gap of 2.55 eV. The anti-bacterial activity results of the as-prepared sample showed a significant inhibition effect against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) bacteria. The author suggests that the current study opens a great horizon for employing mineral salts in drinking water and plant extracts in the fabrication of nanomaterials. [ABSTRACT FROM AUTHOR]

The biological methods are considered as environmental-eco-friendly methods for the silver nanocomposites mediation and are widely used in this context. However, the biological methods go along with the relevant limitations, for instance simultaneous synthesis of silver chlorides (AgNCl) type during the AgNPs mediation process. Therefore, the present research is coming to summarize several aspects in this context. Firstly, to present the possible promotion of the sustainable development using bioactive source (e.g. milk) as a source of two different available and new lactobacillus strains (Lactobacillus curvatus and Lactobacillus fermentum). Secondly, to show the ability of the respective isolates to be involved in mediation of various biosilver nanocomposites ((Bio)NCs) synthesis. Moreover, at this stage, for the first time, two (Bio)NCs mediation methods, called "direct method" and "modified method", have been developed, thus three types (AgNPs, AgNCl and AgNP@AgNCl) of nanocomposites mediated by two different Lactobacillus isolates take place. The interdisciplinary approach included using several spectroscopic, microscopic, spectrometric and thermogravimetric methods demonstrated that all six synthesized nanoparticles (three AgNPs, AgNCl and AgNP@AgNCl types from each source) consist of complex structure including both metallic silver core as well as organic surface deposits. The spectrometric technique allowed to identification of the organics branching surface, naturally secreted by the used Lactobacillus isolates during the inoculation step, suggesting the presence of amino-acids sequences which are direct connected with the reduction of silver ion to metal silver, and subsequently with the formation of coated (Bio)NCs and nucleation process. Moreover, based on the obtained results, the mediation mechanism of each (Bio)NCs has been proposed, suggesting that the formation of AgNPs, AgNCl and AgNP@AgNCl types occurs in different manners with faster synthesis firstly of AgNCl, then of the AgNPs type. No differences between the (Bio)NCs synthesized by two different Lactobacillus isolates have been noticed indicating no discrepancies between metabolites secreted by the respective sources. [ABSTRACT FROM AUTHOR]

The fabrication of the Screen‐Printed Electrode (SPE) was performed using the graphite ink to print the working (WE) and counter electrodes (CE), and silver/silver chloride path as reference electrode (RE). All the electrodes are printed in a paper substrate using screen‐printing technique. The resulting SPE is characterized using scanning electron microscopy, showing all the ink layer, and subsequently optimized. The paper sample presented the cellulose fibers entanglement, extremely rough, with highly porous network. Then the graphite ink was deposited and the surface became flat, thinner and very smooth. When the silver ink was painted on top of the graphite ink, the spherical silver particles, ranged from 2–3.5 μm in size, were observed. And finally, the silver ink was covered with a AgCl layer and the particle size becomes larger with an irregular sphere‐like phase. The images showed that the layers appear to be homogeneously distributed with good coverage. Then fabrication process was optimized concerning type of paper, the sanding process, the hydrophobic barrier, the electrode design and size. In summary, the optimized values included using the previously sanded matte paper with a mineral spirit layer. The design and size of the electrode were also tested to achieve the best electrochemical performance (design 3 with 3.5 cm). The final SPE was a miniaturized and flexible paper‐based electrochemical electrode. In order to evaluate the electrical properties, the ohmic resistance of each ink was tested using a multimeter and the obtained values were 2.18 kΩ for the graphite ink, 2.27 Ω for the silver ink and 38.33 kΩ for the silver/silver chloride ink. That can indicate the good conductivity of each ink used in the fabrication of the electrode and the correct deposition of Ag/AgCl. Finally, the electrode was used to measure the electrochemical response of K4[Fe(CN)6] in different concentrations. Then a calibration curve was obtained from the voltammograms and a linearity was observed between the current and concentration in the range of 0.50–2.00 mM. That indicates that the SPE has potential to be used as a voltammetric electrode. [ABSTRACT FROM AUTHOR]

The control of product quality in precipitation systems is often difficult due to high supersaturation levels and fast kinetics. Rapid and uniform mixing of fluids is required to minimize supersaturation gradients before the onset of nucleation. This study proposes an active mixing platform utilizing induced-charge electroosmosis (ICEO) to better control crystal quality attributes such as the size distribution. The mixing performance of the ICEO-based micromixer is characterized through experiments as a function of the solution properties and the electric field parameters such as phase angle, frequency, and voltage. Optimal mixing is achieved at lower conductivities when the phase difference is 180°. Furthermore, computational fluid dynamics simulations demonstrate that uniform supersaturation is achieved at shorter mixing lengths of the device along with a narrower residence time distribution in the presence of ICEO. Additionally, the performance of the ICEO-based crystallizer is demonstrated for the reactive precipitation of silver chloride particles and carbamazepine-succinic acid cocrystals. The application of ICEO leads to the production of smaller silver chloride particles with a narrower size distribution and an improved yield for cocrystallization compared to cases without ICEO. The ICEO-based micromixer characterized in this work is generally attractive for the continuous production of particles through reactive precipitation with stringent requirements on product uniformity and yield. • Mixing characterization of an ICEO-based micromixer for reactive precipitation. • More uniform supersaturation levels are achieved with ICEO. • ICEO-based micromixer produces small AgCl particles with narrow size distribution. • Improvement in cocrystal yield with application of ICEO. [ABSTRACT FROM AUTHOR]