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The present study focused on evaluating the antibacterial properties, radical scavenging, and photocatalytic activities of Centaurea behen-mediated silver nanoparticles (Cb-AgNPs). The formation of Cb-AgNPs was approved by UV–Vis spectrometry, Fourier-transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction. The results showed that the obtained AgNPs have a maximum absorbance peak at 450 nm with spherical morphology and an average size of 13.03 ± 5.8 nm. The catalytic activity of the Cb-AgNPs was investigated using Safranin O (SO) solution as a cationic dye model. The Cb-AgNPs performed well in the removal of SO. The coupled physical adsorption/photocatalysis reaction calculated about 68% and 98% degradation of SO dye under solar irradiation. The Cb-AgNPs inhibited the growth of gram-negative or positive bacteria strains and had excellent DPPH radicals scavenging ability (100% in a concentration of 200 µg/ml) as well as a good effect on reducing coagulation time (at concentrations of 200 and 500 µg/mL reduced clotting time up to 3 min). Considering the fact that green synthesized Cb-AgNPs have antioxidant and antibacterial properties and have a good ability to reduce coagulation time, they can be used in wound dressings. As well as these NPs with good photocatalytic activity can be a suitable option for degrading organic pollutants. [ABSTRACT FROM AUTHOR]

Electrospinning has garnered much attention for skin renewal, emphasizing skin's pivotal role as a primary protective layer and the susceptibility to loss caused by burns. The research aimed to develop a multipurpose wound dressing that safeguard injuries and facilitates the renewal of dermal tissues. Two-layer nanofibers were prepared using polyvinyl alcohol–chitosan–gelatin/polyacrylonitrile (PVA–CS–Gel/PAN), containing mupirocin (Mu 3% w/w) in underlying layer and silver nanoparticles (AgNps) in the upper layer with varying concentrations. AgNps were synthesized from Capsella bursa-pastoris extract by the green method and characterized using XRD, SEM, FTIR, and UV techniques. Then, PVA–CS–Gel/PAN solutions with AgNps and Mu were electrospun into multilayer dressings. The effectiveness of the nanofibers was evaluated through in vitro and in vivo tests. The study examined the nanofibers containing spherical AgNps with an average diameter of 72.57 nm and a negative surface charge (− 12 mv). They had uniform and smooth surfaces with a diameter range of 476.31 to 926.04 nm. According to swelling and contact angle results, hydrophilicity of samples had a direct relation with water absorption. Controlled drug release within 72 h followed Higuchi or first-order profiles. MTT and antibacterial analyses indicated that optimized nanofibers (Mu/1% AgNps) had suitable biocompatibility and synergistic potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. Additionally, an in vivo test on rats with second-degree burns after 28 days demonstrated a 98.97% improvement in revival, outperforming its commercial counterparts. Consequently, the results position the designed composite nanofiber as a promising candidate for wound healing applications, aiding in enhancing skin regeneration. [ABSTRACT FROM AUTHOR]

Super hydrophobic porous silicon surface is prepared using a wet chemical synthesis route. Scanning electron microscopic investigation confirms a correlation between pore size and reaction time. SERS substrates are prepared by silver nanoparticle deposition on porous silicon surface. They exhibit excellent characteristics in terms of sensitivity, reproducibility, stability, and uniformity. They could detect rhodamine 6G in femtomolar range with SERS enhancement factor of ~ 6.1 × 1012, which is best ever reported for these substrates. Molecule-specific sensing of water pollutants such as methylene blue, glyphosate, and chlorpyrifos, is demonstrated for concentrations well below their permissible limits along with excellent enhancement factors. Porous silicon substrate functionalized with Ag nanoparticles demonstrates to be a promising candidate for low-cost, long-life, reliable sensors for environmental conservation applications. [ABSTRACT FROM AUTHOR]

Silver nanoparticles are widely utilized in printed electronics for forming conductive lines due to their exceptional electrical conductivity, resistance to oxidation, and mechanical reliability. Molecular dynamics simulations are employed to monitor real-time sintering behavior at the atomic scale. This feat is challenging to achieve through experimental means. Thermal properties, including melting points and sintering behaviors, are theoretically characterized across a range of particle sizes (from 3 nm to 20 nm). This study analyzes the melting behavior of multi-sized silver nanoparticles and simulates the structural evolution and morphology changes during the sintering process. The simulations reveal noteworthy phenomena, such as variations in melting points, gyration radii, and mean square displacements based on different particle sizes. Additionally, an optimal sintering temperature is determined through shrinkage coefficient calculations. These simulation outcomes shed light on phenomena at the atomic level, presenting a theoretical foundation for optimizing conductive ink formulation and refining sintering conditions. [ABSTRACT FROM AUTHOR]

Bacterial plant diseases are difficult to control as the durability of deployed control measures is thwarted by continuous and rapid changing of bacterial populations. Although application of copper compounds to plants is the most widespread and inexpensive control measure, it is often partially efficacious for the frequent appearance of copper-resistant bacterial strains and it is raising concerns for the harmful effects of copper on environment and human health. Consequently, European Community included copper compounds in the list of substances candidates for substitution. Nanotechnologies and the application of nanoparticles seem to respond to the need to find new very effective and durable measures. We believe that Argirium-SUNCs®, silver ultra nanoclusters with an average size of 1.79 nm and characterized by rare oxidative states (Ag2+/3+), represent a valid candidate as a nano-bactericide in the control of plant bacterial diseases. Respect to the many silver nanoparticles described in the literature, Argirium-SUNCs have many strengths due to the reproducibility of the synthesis method, the purity and the stability of the preparation, the very strong (less than 1 ppm) antimicrobial, and anti-biofilm activities. In this mini-review, we provide information on this nanomaterial and on the possible application in agriculture. Key points: • Argirium-SUNCs have strong antimicrobial activities against phytopathogenic bacteria. • Argirium-SUNCs are a possible plant protection product. • Argirium-SUNCs protect tomato plants against bacterial speck disease. [ABSTRACT FROM AUTHOR]

Many products contain silver nanoparticles, which are adsorbed by living organisms and then go through biological barriers. In particular, penetration of silver nanoparticles through the placental barrier is likely to damage the offspring. Here, we review hazards of silver nanoparticles with focus on exposure during pregnancy, toxicokinetics at maternal and fetal layers, ex vivo and in vivo placenta transfer models, and factors affecting the transfer. Exposure occurs by oral uptake, inhalation, dermal contact, and systemic administration. Toxicokinetics include absorption, distribution in tissues, metabolism and excretion. The accumulation efficiency is primarily influenced by the mode of exposure. Injection exhibits the highest bioavailability, followed by inhalation and oral uptake. Particles within the range of tens of nanometers are capable of crossing the placenta, according to an ex vivo placental perfusion model. In contrast, larger particles in the range of hundreds of nanometers are expelled outside. Due to the size restriction of the trophoblast channel, which typically ranges from 15 to 25 nm, it is possible for silver nanoparticles with an average size of around 20 nm to passively enter the placenta through the pericellular pathway, such as diffusion. On the other hand, larger silver nanoparticles may be delivered to the placenta through endocytosis, which can occur via phagocytosis, receptor-mediated or independent mechanisms. [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]

With the extensive utilization of nanotechnology, silver nanoparticles (AgNPs) are prevalent nanomaterials that may entail ecological risks by their potential translocation into plant systems. The present study investigated the physiological and molecular responses of basil seedlings (Ocimum basilicum) subjected to AgNPs or silver nitrate (AgNO3) for 7 days. The seedlings were treated with 0, 4, 10, or 40 mg/L of AgNO3 or AgNPs in Hoagland's solution. Both treatments resulted in significant accumulation of Ag in the roots and shoots, with higher levels in the roots of AgNO3-treated seedlings. AgNPs increased plant biomass at 4 mg/L, while AgNO3 decreased it at all concentrations. Both treatments reduced the total chlorophyll, carotenoids, and carbohydrates, with more pronounced effects in AgNO3-treated seedlings. Both treatments also induced oxidative stress, as indicated by increased levels of H2O2, malondialdehyde (MDA), and proline, and enhanced activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). However, these responses were more evident in AgNO3-treated seedlings, especially at higher concentrations. Quantitative real-time PCR analysis revealed that both treatments induced the upregulation of genes encoding oxidative stress tolerance-related enzymes, such as FSD1, MSD1, CSD1, CATa, CATb, APXa and APXb, in the basil seedling shoots. These results suggest that AgNPs are less toxic to basil plants than AgNO3 and that basil plants can activate physiological and molecular mechanisms to cope with Ag-induced oxidative stress. [ABSTRACT FROM AUTHOR]

The unearthing of various forms of broad and narrow-spectrum antibiotics have helped mankind combat various forms of microbic infections ranging from protozoal to bacterial. The applicability of antibiotics has been decisive in a wide range of frontline therapeutic dealings. An extensive use of antibiotics and certain genetic modifications in microbes has paved the way for a new issue to be answered by the scientific community, an antibiotic resistance. An unparallel infections triggered by multidrug-resistant organisms (MDRO) account to be a major cause of mortality and morbidity, today this situation demands the development of alternative strategies of cure and medicine by the scientific community. Study shows the amplification of the effect of antibiotics may be a possible route to address antibiotic resistivity. The assortment of various surface properties of nanoparticles (NPs) coupled with their ability to efficiently bind with bacterial surfaces leading to the rupture and lysis of cell deliberates potential strategies to manage infections caused by MDROs.The present study scrutinizes the amplification of the antibacterial activity of ciprofloxacin (CIP) against the bacterial strains of Staphylococcus aureus, Escherichia coli, Pseudomonas and Streptococcus mutans on coupling with synthesized copper, silver and zinc oxide NPs (ZnO NPs) by disc diffusion technique. The current study describes the efficacious synthesis and characterization of ZnONP, copper Nps (CuNPs) and silver NPs (AgNPs) followed by the induced amplification of the antibacterial activity of CIP by coupling it with synthesized metal/metal oxide (M/MO NP). The synthesized M/MO NPs were characterized using XRD and FE-SEM studies and TEM. The results indicated that among the ZnONP, AgNP, the Cu NPs potentiate the bactericidal efficacy of CIP antibiotics. [ABSTRACT FROM AUTHOR]

An environmentally feasible approach was adopted for the green synthesis of silver nanoparticles (AgNPs) in the BC membrane using Komagataeibacter intermedius (MBS-88) strain. BC production was optimized, resulting in 14.72 g/L of BC when crude glycerol was utilized as a carbon source. The produced BC has a tensile strength of 387 N/m2, an elongation at break % of 2.04, and a Young's modulus of 304 MPa. The bacterial cellulose/AgNP composites have been successfully synthesized using BC as a template via the hydrothermal synthesis in which bacterial cellulose itself acts as a reducing and stabilizing agent. The characterization of the synthesized AgNPs was carried out using electron microscopy (SEM and TEM), Fourier transform infrared microscopy (FT-IR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Adherence of AgNPs to the surface of the BC matrix was observed under SEM. Particle size distribution shows nanoparticles are in the range of 5–45 nm. XRD shows AgNPs peaks at 38.2° (111), 46.3° (200), and 64.5° (220). Peaks of Ag 3d at 367.58 eV and 373.55 eV, along with C 1 s at 284.26 eV and O 1 s at 532.16 eV, were observed in XPS spectra. BC/Ag nanocomposite disk showed better antibacterial activities against Staphylococcus epidermidis ATCC 2228 (6.5 ± 0.1 mm), Staphylococcus aureus 29,213 (6 ± 0.2 mm), and Pseudomonas aeruginosa (5.1 ± 0.2 mm). Thus, the synthesized BC–AgNPs could be used in controlling wound infections as an alternative to chemical synthesis that might have deleterious effects on the ecosystem. [ABSTRACT FROM AUTHOR]

To synthesize silver nanoparticles suspended in deionized water, Elettaria cardamomum (Car) seed extract and Car@Ag nanoparticles were prepared in three steps. The first used a hot aqueous extract of Elettaria cardamomum seed, and then, the second used pulsed laser ablation technique (PLAL) by Nd:YAG laser (λ = 1064 nm wavelength) at laser energy of 400 mJ, and the number of pulses was 500 pulses and third step for the synthesis of creating a non-conjugated Elettaria cardamomum extract. Ultraviolet visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) were used to investigate the optical, structural, and morphological characterizations of synthesized Car@AgNPs. The nanoparticles were spherical in shape, and a size distribution exhibited a mean size of 21 nm, according to the TEM findings. AgNPs and Car@AgNPs have free radical scavenging activity in the DPPH assay. Additionally, Car@AgNPs were examined in vitro for zones of inhibition against pathogenic bacteria like Escherichia coli and Staphylococcus aureus. The inhibition rate of Escherichia coli was higher than that observed in Staphylococcus aureus. Finally, Car@AgNPs demonstrated a potential cytotoxicity agent breast cancer (MCF-7) cell line that was evaluated by MTT assay. [ABSTRACT FROM AUTHOR]

Herein, a convenient and environment-friendly reduction strategy was employed to attach silver nanoparticles onto ceria nanorods (AgCe). Nanorods were synthesised through a green chemistry approach with varied silver contents and Citrus maxima peel extract as a reducing agent. The resulting AgCe nanocomposites were evaluated for their efficacy in reducing methyl orange (MO) at ambient temperature by employing NaBH4 as a protonating agent. The as-prepared samples were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray energy-dispersive spectroscopy, Raman spectroscopy, Brunauer–Emmett–Teller method, and high-resolution transmission electron microscopy. The as-prepared sample exhibited outstanding activity on the catalytic reduction of MO, and the synergistic effect between Ag nanoparticles and CeO2 nanorods was proved. Silver nanoparticles were formed and dispersed well on the surface of ceria nanorods. Based on the UV–Vis results, the activity of the samples with silver was superior to that of pure ceria. The 0.2AgCe sample was the most effective when the catalyst concentration was 0.08 g/L, and the molar ratio between MO and NaBH4 was 1/200. The entire catalytic reduction was thought to follow pseudo-first-order kinetics. Hence, Ag nanoparticles decorated on CeO2 efficiently offered excellent catalytic efficiency and stability in MO reduction and that the catalyst was suitable for practical applications, such as wastewater treatment. [ABSTRACT FROM AUTHOR]

In this study, the biosynthesis and characterization of silver nanoparticles (AgNPs) from orchid tree (Bauhinia variegata) leaf extract were firstly carried out, and then, the usability of AgNPs as a colorimetric sensor for detection of Fe3+ ions in aqueous solutions was evaluated. The characterization studies showed that the synthesized particles were determined to be AgNPs in nanoscale and face-centered cubic structure. Besides, the total phenolic content of B. variegata extract was determined to be 1.826 ± 2.1 mg gallic acid equivalents/g dry leaf. Also, the biosynthesized AgNPs showed a strong surface plasmon resonance (λSPR) around 430 nm and λSPR intensity decreased with the increasing in Fe3+ concentration in aqueous solution. Based on the linear relationship between the change of λSPR intensity and Fe3+ ion concentration, AgNPs can be used for the sensitive and selective detection of Fe3+ ions in aqueous solutions with a linear range of 6-100 μM and a detection limit of 2.08 × 10−6 M. [ABSTRACT FROM AUTHOR]

Cassava root rot disease caused by the fungal pathogens Fusarium solani and Lasiodiplodia theobromae produces severe damages on cassava production. This research was conducted to produce and assess silver nanoparticles (AgNPs) synthesized by Trichoderma harzianum for reducing root rot disease. The results revealed that using the supernatants of T. harzianum on a silver nitrate solution changed it to reddish color at 48 h, indicating the formation of AgNPs. Further characterization was identified using dynamic light scattering (DLS) and scanning electron microscope (SEM). DLS supported that the Z-average size is at 39.79 nm and the mean zeta potential is at − 36.5 mV. SEM revealed the formation of monodispersed spherical shape with a diameter between 60–75 nm. The antibacterial action of AgNPs as an antifungal agent was demonstrated by an observed decrease in the size of the fungal colonies using an increasing concentration of AgNPs until the complete inhibition growth of L. theobromae and F. solani at > 58 µg mL−1 and at ≥ 50 µg mL−1, respectively. At in vitro conditions, the applied AgNPs caused a decrease in the percentage of healthy aerial hyphae of L. theobromae (32.5%) and of F. solani (70.0%) compared to control (100%). The SR-FTIR spectra showed the highest peaks in the first region (3000–2800 cm−1) associated with lipids and fatty acids located at 2962, 2927, and 2854 cm−1 in the AgNPs treated samples. The second region (1700–1450 cm−1) consisting of proteins and peptides revealed the highest peaks at 1658, 1641, and 1548 cm−1 in the AgNPs treated samples. The third region (1300–900 cm−1), which involves nucleic acid, phospholipids, polysaccharides, and carbohydrates, revealed the highest peaks at 1155, 1079, and 1027 cm−1 in the readings from the untreated samples. Finally, the observed root rot severity on cassava roots treated with AgNPs (1.75 ± 0.50) was significantly lower than the control samples (5.00 ± 0.00). [ABSTRACT FROM AUTHOR]

The current research aimed to study the green synthesis of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata (RC) aqueous extract as a potent reducing and stabilizing agent. The obtained RC-AgONPs were characterized using UV, FT-IR, XRD, DLS, SEM, and EDX to investigate the morphology, size, and elemental composition. The size of the RC-AgONPs was found to be ~ 21.66 nm and an almost uniform distribution was executed by XRD analysis. In vitro studies were performed to reveal biological potential. The AgONPs exhibited efficient DPPH free radical scavenging potential (71.3%), reducing power (63.8 ± 1.77%), and total antioxidant capacity (88.5 ± 4.8%) to estimate their antioxidative power. Antibacterial and antifungal potentials were evaluated using the disc diffusion method against various bacterial and fungal strains, and the zones of inhibition (ZOI) were determined. A brine shrimp cytotoxicity assay was conducted to measure the cytotoxicity potential (LC50: 2.26 μg/mL). In addition, biocompatibility tests were performed to evaluate the biocompatible nature of RC-AgONPs using red blood cells, HEK, and VERO cell lines (< 200 μg/mL). An alpha-amylase inhibition assay was carried out with 67.6% inhibition. Moreover, In vitro, anticancer activity was performed against Hep-2 liver cancer cell lines, and an LC50 value of 45.94 μg/mL was achieved. Overall, the present study has demonstrated that the utilization of R. capitata extract for the biosynthesis of AgONPs offers a cost-effective, eco-friendly, and forthright alternative to traditional approaches for silver nanoparticle synthesis. The RC-AgONPs obtained exhibited significant bioactive properties, positioning them as promising candidates for diverse applications in the spheres of medicine and beyond. [ABSTRACT FROM AUTHOR]

Infections related to biomedical devices and materials remain a critical healthcare concern, leading to considerable morbidity and disease burden. To combat this issue, the development of fibers with inherent antibacterial properties has garnered significant interest. These fibers offer a large surface area, making them ideal candidates for effective treatment with antibacterial agents. In this study, we present a straightforward procedure for applying silver nanoparticles (AgNPs) to hydrophobic polylactic acid (PLA) fibers that have been surface-modified using sodium hydroxide (NaOH). The method involved electrospinning to create a high-thickness web of PLA fibers, followed by gradual surface modification with NaOH at two different concentrations (0.5 M and 1 M). To confer antibacterial properties to the modified surface samples, we applied silver nanoparticles (AgNPs) at a concentration of 25 mM. In contrast to regular PLA fibers, the surfaces of hydrolyzed PLA (PLA-H) fibers, AgNPs-treated PLA (PLA-A), and hydrolyzed-AgNPs coated PLA (PLA-H-A) fibers exhibited a non-uniform and highly porous structure. EDX analysis provided crucial information about the presence and integration of Ag nanoparticles into the PLA fibers. The PLA-H-A sample exhibited the highest hydrophilicity, with a contact angle of 65.7°. Additionally, the results from differential scanning calorimetry indicated an increase in PLA-H-A's glass transition temperature. Notably, in the Gram-positive Escherichia coli (E. coli) and Gram-negative Staphylococcus aureus (S. aureus) tests, the PLA-H-A samples demonstrated highly effective antibacterial properties, effectively preventing bacterial growth. [ABSTRACT FROM AUTHOR]

Based on calculations, the spatial distribution of the local electric field (LEF) for various structural configurations of silver nanoparticles (NPs) in silicate and zinc-phosphate glasses was studied. The features of this distribution determine the efficiency of energy transfer from plasmonic NPs to rare earth (RE) ions located in the particle vicinity. The mechanism of energy transfer through field enhancement via surface plasmon resonance of particles, which is dominant for NPs of sizes of ≥ 5 nm, is determined by several factors. To clarify their roles and significance, the dependencies of LEF upon the size, spatial distribution, and degree of agglomeration of silver NPs in glass were studied. Comparative analysis of the nature of the field enhancement in places of hypothetical location of RE ions was carried out on the basis of a visual representation of the spatial distribution of the LEF in the vicinity of agglomerates of plasmonic NPs. Based on simulations, the dependencies of LEF intensity enhancement, the spatial distribution of such places in relation to the nearest plasmonic particle, upon the concentration of NPs, their size, degree of agglomeration, and the presence of small (≤ 5 nm) particles in the sample along with the relatively large ones, were determined. The optimal configuration of silver particles in glass for obtaining the maximum average enhancement of LEF intensity per the site of possible location of RE ion is revealed to be an agglomerate of NPs with sizes slightly larger than 25 nm and average distances between particle centers about 30 nm. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is a leading cause of morbidity and death worldwide. As current cancer drugs are ineffective, new solutions are being sought in other fields, including nanoscience. Similarly, silver nanoparticles play an important role in the pharmaceutical industry as they act as anti-cancer agents with less harmful effects and are usually 1 to 100 nm in size. Selenic acid (SA) and pyruvic acid (PA) are involved in various metabolic pathways in cancer. For this reason, we decided to detect their influence on colorectal cancer using silver-based (Ag) nanocarriers. DLS, Zetasizer, SEM and UV-Vis analyses were used to characterize AgSA and AgPA. A UV spectrophotometer was used to analyze the release of the NPs. MTT analyses were used to measure the viability of HCT116 and HUVEC cells, and IC50 values were calculated using GraphPad Prism. The indicated dosage and particle size of AgSA NPs proved to be suitable for cytotoxicity. Moreover, injection of these nanoparticles into non-cancer cells proved safe due to their minimal toxicity. In contrast, the AgPA NPs have no cytotoxicity and induce proliferation of HCT116 cells. Finally, only the synthesised AgSA nanoparticles could be used for advanced cancer therapy, which is both inexpensive and has minimal side effects. [ABSTRACT FROM AUTHOR]

The use of traditional plants has been tremendously increased due to their higher biological impact, minimal side effects, and comparatively low cost. Moreover, the emergence of antibacterial resistance is also shifting the scientific community to reconsider herbal remedies which provide relatively safer, cheap and biologically tolerable solutions. The present research was designed to fabricate the Mentha spicata conjugated silver nanoparticles (Me-AgNPs). Furthermore, the assessment of the bactericidal potential of Me-AgNPs against various bacterial strains was another motive behind this study. Fabricated NPs were characterized with the help of the UV-Visible spectrophotometric analysis, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). Me-AgNPs showed a significant zone of inhibition (23 ± 0.2 mm) at 8 mg/mL against Staphylococcus aureus and a 4.0 ± 0.2 mm zone of growth inhibition at 2 mg/mL against Aeromonas veronii. The stability of Me-AgNPs was assessed at various pH (4, 7 and 11) and temperatures (25 °C, 4 °C, 37 °C, 75 °C). The significant zones of inhibition (11.3 ± 0.3 mm, 8.3 ± 0.3mm, 14.3 ± 0.3 mm, and 7.6 ± 0.2 mm) were observed at pH 11 against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae, respectively. Growth inhibition zones (14.0 ± 0.5 mm and 13.0 ± 0.5 mm) were also determined against B. subtilis and S. aureus at 25 °C. DPPH bioassay was conducted to find the antioxidant properties of Me-AgNPs. The highest (38.66 ± 0.2%) free radical scavenging activity was shown by Me-AgNPs at 4 mg/mL. Present study results concluded that biogenic Me-AgNPs have bactericidal as well as anti-oxidative potential. Moreover, these green synthesized Me-AgNPs could maintain their potency and stability at a wide range of pH and temperature. [ABSTRACT FROM AUTHOR]

Candida species is the causative agent in approximately 80% of invasive mycoses and drug-resistant Candida albicans is among the four strains of 'critical priority group' framed by WHO. Lichens are endowed with some rare phytochemicals and a plethora of therapeutics viz. antifungal capacities of Roccella montagnei. Biosynthesis of silver nanoparticles (AgNPs) using lichen could offer an eco-friendly, and cost-effective alternative against emerging 'microbial resistance.' Therefore, the objective was to biosynthesize silver nanoparticles (Rm-AgNPs) using a Hydro-alcoholic (1:1) extract of R. montagnei to develop a potent anticandidal agent against Fluconazole-resistant C. albicans NBC099. UV-Spectroscopy identified AgNPs specific-peak of Rm-AgNPs at 420–440 nm and FTIR revealed the presence of amines, alcohol, aromatic compounds, and acids. SEM and TEM analysis indicated that Rm-AgNPs are spherical shaped with a size range of 10–50 nm. Zetasizer analysis indicated that particles are highly stable and have a mean hydrodynamic diameter of 116 nm with a zeta potential charge of − 41 mV. XRD analysis suggested face centered cubic crystal lattice structure. Results indicated that Rm-AgNPs strongly inhibited the growth of NBC099 at a minimum inhibitory concentration (IC50) of ≤ 15 µg. C. albicans culture treated with Rm-AgNPs at concentrations below IC50, down-regulates the production of different virulence factors in NBC099, viz. hyphal formation (> 85%), biofilms production (> 80%), phospholipase, esterase, proteinase activity. The apoptosis assay demonstrated the Rm-AgNPs induced apoptosis in NBC099 cells via oxidative stress. Interestingly, Rm-AgNPs showed negligible cytotoxicity (< 6%) in murine RAW 246.7 macrophage cells at a concentration above 15 µg/mL. Therefore, Rm-AgNPs have been offered as an anti-candida alternative that can be utilized to improve the efficacy of already available medications. [ABSTRACT FROM AUTHOR]

Three different types of carbon screen-printed electrodes consisting of mesoporous carbon (MC), carbon nanofibers (CNF), and single-walled carbon nanotubes (SWCNT) were used as carbon supports for deposition of Ag, in the absence of reductant in the plating solution. The SPEs were characterized by Raman spectroscopy and show marked differences in their structure. To drive the metal deposition, the carbon supports were potentiostatically pre-treated in supporting electrolyte. The metal deposition occurred in AgNO3 solution and resulted in the formation of homogeneously distributed metal nanoparticles with type and amount depending on both the potential used in the pre-treatment step and the structure of the carbon electrodes. Larger metal amounts and higher particle densities (in the 109 cm−2 range) together with smaller particle mean sizes (in the 40- to 60-nm range) were obtained by using more negative potential for the pre-treatment. A further way to influence the characteristics of the metal deposit was based on double or triple consecutive pre-treatment/deposition cycles. The obtained results are discussed in view of the possible sources of electron supply, necessary for the formation of the metal particles on the carbon carrying substrates. [ABSTRACT FROM AUTHOR]

Thymus daenensis Celak. (T. daenensis) essential oil (TDO) was encapsulated into beta-cyclodextrin (β-CD) by co-precipitation method and incorporated into polylactic acid (PLA) films along with silver nanoparticles (AgNPs) to generate the active PLA film for extending the ground beef shelf life at 4 °C. Scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FTIR) confirmed the proper dispersion of AgNPs, TDO, and β-CD/TDO throughout the PLA films. Different physical properties were observed in the active PLA films, so that the addition of β-CD/TDO in the films increased the thickness and decreased the tensile strength (TS) and elongation at break compared to TDO films. The color of the AgNP films was lightly darker than the others. The microbial evaluation of the packaged ground beef samples with active PLA films indicated that accompanying AgNPs with β-CD/TDO and TDO could synergistically inhibit total viable bacteria counts, psychrotrophic bacteria counts, and Enterobacteriaceae counts during the sample's storage for 12 days. This effectiveness was also observed in controlling changes in pH and total volatile basic nitrogen (TVB-N) in the samples. Considering the efficient entrapment of TDO in β-CD, the shelf life of samples was significantly extended, due to sustained and long-lasting release of the essential oil compounds, compared to the net TDO films. Based on the results, it can be concluded that β-CD/TDO+AgNP film can be a promising approach to extend the shelf life of ground beef. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag NPs) were synthesized in biogenic methods. It is aimed to improve the electrochemical sensor efficiency of synthesized Ag NPs against the pharmaceutical drug paracetamol. For this purpose, fourier transmission infrared spectroscopy (FTIR), ultra-violet visible spectroscopy (Uv–vis), X-ray differentiation (XRD), and transmission electron spectroscopy (TEM) analyses were performed to elucidate the structure of the synthesized Ag NPs. In the TEM characterization results, the mean size of the NPs was found to be 19.035 nm using TEM characterization and the XRD results, the crystalline size of the NPs was 11.66 nm. Sensor studies were performed with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Paracetamol showed a sensitivity of approximately 0.4 V to Ag NPs in this study. The linear ranges of this study are 6.5–14.5 µM, with a limit of detection (LOD) of 5.79 µM and a limit of quantification (LOQ) of 17.56 µM. [ABSTRACT FROM AUTHOR]

A perennial challenge in harnessing the rich biological activity of medicinal and edible plants is the accurate identification and sensitive detection of their active compounds. In this study, an innovative, ultra-sensitive detection platform for plant chemical profiling is created using surface-enhanced Raman spectroscopy (SERS) technology. The platform uses silver nanoparticles as the enhancing substrate, excess sodium borohydride prevents substrate oxidation, and methanol enables the tested molecules to be better adsorbed onto the silver nanoparticles. Subsequently, nanoparticle aggregation to form stable "hot spots" is induced by Ca2+, and the Raman signal of the target molecule is strongly enhanced. At the same time, deuterated methanol was used as the internal standard for quantitative determination. The method has excellent reproducibility, RSD ≤ 1.79%, and the enhancement factor of this method for the detection of active ingredients in the medicinal plant Coptis chinensis was 1.24 × 109, with detection limits as low as 3 fM. The platform successfully compared the alkaloid distribution in different parts of Coptis chinensis: root > leaf > stem, and the difference in content between different batches of Coptis chinensis decoction was successfully evaluated. The analytical technology adopted by the platform can speed up the determination of Coptis chinensis and reduce the cost of analysis, not only making better use of these valuable resources but also promoting development and innovation in the food and pharmaceutical industries. This study provides a new method for the development, evaluation, and comprehensive utilization of both medicinal and edible plants. It is expected that this method will be extended to the modern rapid detection of other medicinal and edible plants and will provide technical support for the vigorous development of the medicinal and edible plants industry. [ABSTRACT FROM AUTHOR]

The effect of silver nanoparticles and surfactant micelles on their joint presence on the intensity of the sensitized fluorescence of the norfloxacin complex with the Tb3+ ion is studied. It is shown that the intensity of the intrinsic fluorescence of norfloxacin and its complex with Tb3+ ions in the presence of silver nanoparticles decreases slightly. It is found that, in the presence of dodecyl sulfate micelles, a modification of the surface of silver nanoparticles occurs, which is accompanied by a change in the ζ-potential of the nanoclusters. Additions of surfactant-modified silver nanoparticles to aqueous solutions of terbium chelate contribute to an 11-fold increase in the intensity of the sensitized fluorescence. An increase in the efficiency of intramolecular energy transfer in the Tb3+ complex with norfloxacin in the presence of silver nanoparticles and dodecyl sulfate micelles made it possible to propose a method for the fluorimetric determination of the antibiotic in natural water in the concentration range 2 × 10–7−1 × 10–5 M. The equation of the calibration graph is y = 1.0 × 107x − 1.0, R2 = 0.991, the limit of detection is 5 × 10–8 M (3σ). [ABSTRACT FROM AUTHOR]

Our study focused on the optical behavior, methylene blue (MB) dye degradation potential, antibacterial performance, and silver and trioxide mineral interaction with different bacterial species. We found that the addition of silver nanoparticles (Ag NPs) to neodymium oxide (Nd2O3) resulted in a significant response, with an enlargement of the inhibition zone for bacterial species such as Staphylococcus aureus and Escherichia coli. Specifically, the inhibition zone for S. aureus increased from 9.3 ± 0.5 mm for pure Nd2O3 to 16.7 ± 0.4 mm for the Ag/Nd2O3 nano-composite, while for E. coli, it increased from 8.8 ± 0.4 mm for Nd2O3 to 15.9 ± 0.3 mm for Ag/Nd2O3. Furthermore, the optical behavior of the composites showed a clear band-gap narrowing with the addition of Ag NPs, resulting in enhanced electronic localization. The direct and indirect transitions reduced from 6.7 to 6.1 eV and from 5.2 to 2.9 eV, respectively. Overall, these results suggest that the Ag/Nd2O3 nano-composite has potential applications in sensor industries and water treatment, thanks to its enhanced optical behavior, antibacterial performance, and efficient MB degradation capabilities. In terms of MB degradation, the Ag/Nd2O3 mixed system exhibited more efficient degradation compared to pure Nd2O3. After 150 min, the MB concentration in the mixed system decreased to almost half of its starting point, while pure Nd2O3 only reached 33%. [ABSTRACT FROM AUTHOR]

In recent years, there has been an increasing interest in the green synthesis of metallic nanoparticles, mostly because of the evident limitations associated with chemical and physical methods. Green synthesis, commonly referred to as "biogenic synthesis," is seen as an alternative approach to produce AgNPs (silver nanoparticles). The current work focuses on the use of Asterarcys sp. (microalga) for biological reduction of AgNO3 to produce AgNPs. The optimal parameters for the reduction of AgNPs were determined as molarity of 3 mM for AgNO3 and an incubation duration of 24 h at pH 9, using a 20:80 ratio of algal extract to AgNO3. The biosynthesized Ast-AgNPs were characterised using ultraviolet–visible spectroscopy (UV–Vis), zeta potential, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) patterns. The nanoparticles exhibited their highest absorption in the UV–visible spectra at 425 nm. The X-ray diffraction (XRD) investigation indicated the presence of characteristic peaks at certain angles: 38.30° (1 1 1), 44.40° (2 0 0), 64.64° (2 2 0), and 77.59° (3 1 1) according to the JCPDS file No. 04-0783. Based on SEM and TEM, the Ast-AgNPs had an average size of 35 nm and 52 nm, respectively. The zeta potential was determined to be − 20.8 mV, indicating their stability. The highest antibacterial effectiveness is shown against Staphylococcus aureus, with a zone of inhibition of 25.66 ± 1.52 mm at 250 μL/mL conc. of Ast-AgNPs. Likewise, Ast-AgNPs significantly suppressed the growth of Fusarium sp. and Curvularia sp. by 78.22% and 85.05%, respectively, at 150 μL/mL conc. of Ast-AgNPs. In addition, the Ast-AgNPs exhibited significant photocatalytic activity in degrading methylene blue (MB), achieving an 88.59% degradation in 120 min, revealing multiple downstream applications of Ast-AgNPs. [ABSTRACT FROM AUTHOR]

The production of alternative and effective medicines is crucial given that antibiotic resistance is currently a global health concern. Several biochemical identification tests were used to screen for Staphylococcus aureus isolates. Analysis of Artemisia annua extract was performed using a trace GC--mass spectrometer, which revealed that the A. annua extract contains numerous compounds, such as artemisinins, palmitic acid and other vital essential compounds that have antioxidant and anti-inflammatory properties. The isolate st.8 was resistant to cefoxitin, oxacillin, and cephalosporins; furthermore, MALDI-TOF/MS Biotyper® identified it as methicillin-resistant S. aureus with confidence value 99.9% of mass spectrum compared with reference spectra. The synthesis of green silver nanoparticles based on A. annua as a reducing agent was confirmed via partial characterizations: (HR-TEM), (XRD), (SEM), (EDX) and (FTIR) analysis. The significant of antibacterial activity of the new green material (AgNPs) was achieved by determining the agar well diffusion assay. Furthermore, compared with those in the Staphylococcus-infected group, a significant decrease in hematological parameters was observed, with an increase in antioxidant biomarkers, a decrease in interstitial tissue thickening by inflammatory cells, and a weak positive immune reaction in a few cells (TNF-α and iNOS) in rats. Overall, this study is a promising step toward the development of new and effective strategies for combating MRSA infections. [ABSTRACT FROM AUTHOR]

Nanobiotechnology has achieved great advances in the field of scientific research in past years. Nanoparticles (NPs) with diameters ranging from 1 to 100 nm are the focus of nanotechnology. Green synthesis of encapsulated silver nanoparticles (eAgNPs) was carried out by using Solidago virgaurea L. (SvL) and Tussilago farfara L. (TfL) extract as reducing/protecting agent. An UV–vis spectrophotometer was used to determine the optimal conditions to produce eAgNPs from plant extracts, including pH, temperature, plant extract, and mixing times. The optimal conditions for AgNPs synthesis from the SvL plant and TfL plant were (1:1) extract-AgNO3, 24 h mixing time, and a temperature of 25 °C. SEM, TEM, FTIR, and UV–Vis Spectrophotometer analyses were carried out to ascertain the surface characterization and structural properties of eAgNPs and the nanofibrous mats' physicochemical characteristics. The results of the analysis revealed that the eAgNPs are nanosized and contain silver. eAgNPs-doped nanofiber production from polylactide acid (PLA) polymer was realized by electrospin method. The required production parameters for the electrospinning method of producing PLA-based nanofibers were investigated. Nanofiber was produced by combining 0.5 and 1% AgNPs in an 8% PLA solution. The biological effects of the developed PLA@eAgNPs nanofibrous mats were examined in vitro. The antibacterial activity of nanofibers against E. coli was determined using the agar diffusion method. eAgNPs and PLA-based nanostructured materials are suggested as bioactive coatings capable of preventing the development of microbial population on surfaces relevant to healthcare. [ABSTRACT FROM AUTHOR]

Polymer-based sponges loaded with antibacterial agents are potential wound dressings ideal for treating bacteria-infected wounds. Gelatin/poly (ethylene glycol) (PEG) sponge-based wound dressings loaded with metronidazole and Ag nanoparticles with different degrees of cross-linking were prepared, and their capability to treat infected wounds in vitro was evaluated. The degree of cross-linking of the sponges varied, and the porosity of the sponges was in the range of 15.64–91.10%. The amount of gelatin used to prepare the sponges influenced the porosity of the sponges. The sponges displayed an initial burst drug release of metronidazole followed by a sustained release profile. The sponges exhibited considerable antibacterial activity against Gram-positive and Gram-negative bacteria. The % cell viability of the sponges was in the range of 71.17–86.10%, indicating distinguished biocompatibility. The in vitro experiment showed that the sponge loaded with metronidazole, SAM2%, displayed a significant reduction of 66.68% in the scratch area compared to the sponge loaded with a combination of silver nanoparticles and metronidazole with a closure rate of 46.61% at 96 h. The promising features of the sponges indicate that they are potential wound dressings for treating infected wounds. [ABSTRACT FROM AUTHOR]

A method is proposed for the synthesis of new supramolecular structures consisting of silver nanoparticles (NP), the surface of which is covered with spontaneously formed ordered micelle-like aggregates of cetyltrimethylammonium bromide (CTMAB) molecules. In studying the processes of the self-assembly of CTMAB molecules on the surface of silver nanoparticles and the structure of associates formed in this case, the method of fluorescent probes (molecular probe pyrene) is used. The optimal conditions for obtaining new supramolecular structures are determined. The proposed supramolecular structures can be used for the luminescence determination of various chemical compounds. At that the formation of an analytical signal will be determined by the interaction of the analyte with micelle-like aggregates located near the silver NP and will depend on both the structure of the aggregate and the polarity of the analyte. [ABSTRACT FROM AUTHOR]

With the growing resistance of pathogenic microbes to traditional drugs, biogenic silver nanoparticles (SNPs) have recently drawn attention as potent antimicrobial agents. In the present study, SNPs synthesized with the aid of orange (Citrus sinensis) peel were engineered by screening variables affecting their properties via Plackett–Burman design. Among the variables screened (temperature, pH, shaking speed, incubation time, peel extract concentration, AgNO3 concentration and extract/AgNO3 volume ratio), pH was the only variable with significant effect on SNPs synthesis. Therefore, SNPs properties could be enhanced to possess highly regular shape with zeta size of 11.44 nm and zeta potential of − 23.7 mV. SNPs purified, capped and stabilized by cloud point extraction technique were then checked for their antimicrobial activity against Bacillus cereus, Listeria innocua, Listeria monocytogenes, Staphylococcus aureus, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhimurium and Candida albicans. The maximum antimicrobial activity of SNPs was recorded against E. coli, L. monocytogenes and C. albicans with clear zone diameter of 33.2, 31.8 and 31.7 mm, respectively. Based on minimum inhibition concentration and minimum bactericidal concentration of SNPs (300 mg/l) as well as their effect on respiratory chain dehydrogenases, cellular sugar leakage, protein leakage and lipid peroxidation of microbial cells, E. coli was the most affected. Scanning electron microscopy, protein banding and DNA fragmentation proved obvious ultrastructural and molecular alterations of E. coli treated with SNPs. Thus, biogenic SNPs with enhanced properties can be synthesized with the aid of Citrus peel; and such engineered nanoparticles can be used as potent antimicrobial drug against E. coli. [ABSTRACT FROM AUTHOR]

This study was divided into two parts. The first part involved the isolation, and detection of the prevalence and antimicrobial resistance profile of Aeromonas hydrophila, Pseudomonas aeruginosa, and Vibrio species from Nile tilapia fish and marine aquatic water. One hundred freshly dead Nile tilapia fish were collected from freshwater aquaculture fish farms located in Al-Abbassah district, Sharkia Governorate, and 100 samples of marine aquatic water were collected from fish farms in Port Said. The second part of the study focused on determining the in vitro inhibitory effect of dual-combination of AgNPs-H2O2 on bacterial growth and its down regulatory effect on crucial virulence factors using RT-PCR. The highest levels of A. hydrophila and P. aeruginosa were detected in 43%, and 34% of Nile tilapia fish samples, respectively. Meanwhile, the highest level of Vibrio species was found in 37% of marine water samples. Additionally, most of the isolated A. hydrophila, P. aeruginosa and Vibrio species exhibited a multi-drug resistance profile. The MIC and MBC results indicated a bactericidal effect of AgNPs-H2O2. Furthermore, a transcriptional modulation effect of AgNPs-H2O2 on the virulence-associated genes resulted in a significant down-regulation of aerA, exoU, and trh genes in A. hydrophila, P. aeruginosa, and Vibrio spp., respectively. The findings of this study suggest the effectiveness of AgNPs-H2O2 against drug resistant pathogens related to aquaculture. [ABSTRACT FROM AUTHOR]

Investigating the application of innovative antimicrobial surface coatings on medical devices is an important field of research. Many of these coatings have significant drawbacks, including biocompatibility, coating stability and the inability to effectively combat multiple drug-resistant bacteria. In this research, we developed an antibiofilm surface coating for medical catheters using biosynthesized silver nanoparticles (b-Cs-AgNPs) developed using leaves extract of Calliandra surinamensis. Various characterization techniques were employed to thoroughly characterize the synthesized b-Cs-AgNPs and c-AgNPs. b-Cs-AgNPs were compatible with human normal kidney cells and chicken embryos. It did not trigger any skin inflammatory response in in vivo rat model. b-Cs-AgNPs demonstrated potent zone of inhibition of 19.09 mm when subjected to the disc diffusion method in E. coli confirming strong antibacterial property. Different anti-bacterial assays including liquid growth curve, colony counting assay, biofilm formation assay supported the potent antimicrobial efficacy of b-Cs-AgNPs alone and when coated to medical grade catheters. Mechanistic studies reveal the presence of ferulic acid, that was important for the synthesis of b-AgNPs along with enhanced antibacterial effects of b-Cs-AgNPs compared to c-AgNPs, supported by molecular docking analysis. These results together demonstrated the effective role b-Cs-AgNPs in combating infections and mitigating biofilm formations, highlighting their need for further study in the field of biomedical applications. Schematic Illustration of Eco-Friendly Synthesis for Biofilm Prevention on Medical Catheters and Bacterial Infection Mitigation. Created with BioRender.com. [ABSTRACT FROM AUTHOR]

Here, the room temperature deposition of silver (Ag) nanoparticles (NPs) on silicon (Si) substrate has been carried out by a simple chemical route to investigate their elastic and micro-structural properties. The theoretical X-ray peak profile analysis has been pursued through the Scherrer model, modified Scherrer model, modified Williamson–Hall model, size–strain plot model and Halder–Wagner model. The X-ray diffraction (XRD) analysis results in the crystalline nature of Ag NPs having nearer dodecahedron structure. The parameters including micro-strain, internal stress and energy density have been estimated for all reflection peaks of XRD. The findings show that the nano-crystalline size (NCS) estimated from all models is in reasonably good agreement. This analysis can pave the way for novel research avenues by comparing the estimated elastic and micro-structural properties of Ag NPs as a potential alternative tool to existing characterization techniques and helpful in fabricating different sizes of Ag–Si nanostructure-based gas-sensing devices. The influence of Ag nanoparticles on Si nanowire towards acetone gas sensor has been studied and achieved remarkable sensitivity 98.77% at 5 MHz frequency with operating temperature at 50 °C. [ABSTRACT FROM AUTHOR]

The increase in the resistance of microorganisms to existing antibiotics associated with their ability to survive in biofilms makes the development of new antimicrobial agents a topical question. Of great interest in this field are nanocomposites based on halloysite and silver nanoparticles, since they have a broad antimicrobial activity and can reduce the toxic effects of nanoparticles. In this study, we assessed the effect of the AgHNT nanocomposite at a concentration of 0.5 mg/ml on the pathogenicity factors of Serratia marcescens. The antibiofilm activity of AgHNT was assessed by resazurin assay, and visualized using light and AFM microscopy. AgHNT were found to significantly inhibit biofilm formation in S. marcescens. Although the silver-containing species did not affect protease activity, they greatly reduced the production of prodigiosin, another quorum-sensing factor, by bacteria. The AgHNT nanocomposite was more efficient in suppressing S. marcescens biofilms than the antibiotic streptomycin. [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]

Photochemical reduction is used to develop many methods of creating biologically active substances and materials consisting of silver nanoclusters, which makes them relevant for science and technology, including different trends in biotechnology, catalytic systems, label-free quantification, metasurfaces and nanohybrid composites. The paper presents the silver nanoparticle (AgNP) technology based on cavitation-diffusion photochemical reduction in the presence of 10 mg of ligand (polyvinylpyrrolidone) allowing to significantly change the AgNP content depending on the concentration of silver nitrate (AgNO3) in the reaction system, and providing the AgNP domination having a certain size. It is found that at 5 mg of AgNO3 in the reaction system, the size of at least 60% of synthesized nanoparticles, is 26 nm or more, while at 2.5 mg of AgNO3, up to 94.7% of nanoparticles have the size of 15 nm and less, 6 to 10 nm AgNPs being dominated. This meets the need for AgNPs of a certain the size in different fields of science and technology, including medical and pharmaceutical industries, agriculture, and laboratory diagnostics. [ABSTRACT FROM AUTHOR]

Due to their unique properties, organosols of silver nanoparticles are widely used in optical and semiconductor devices, to produce electrically and thermally conductive films, as catalysts, antibacterial materials, etc. This work proposes a simple and highly productive method for the preparation of silver organosols, which have a metal concentration as high as 1800 g/L and contain spherical nanoparticles with low polydispersity and a median size of 9.1 nm. The method consists in the initial preparation of silver nanoparticle hydrosols with a concentration of higher than 30 g/L followed by the transfer of the NPs into an organic phase of o-xylene. A set of physical research methods has been employed to study the regularities of the extraction of silver nanoparticles with o-xylene in the presence of cetyltrimethylammonium bromide (CTAB) and ethanol and to determine the optimal process conditions, under which the extraction degree is as high as 62.5%. It has been found that bromine anions contained in CTAB molecules cause the aggregation of some amount of silver nanoparticles with the formation of silver metal sediment in the aqueous phase. According to X-ray photoelectron spectroscopy data, the sediment contains bromide ions (up to 4 at %) on the particle surface. Organosols synthesized under optimal conditions are stable for more than 7 months and withstand repeated cycles of drying and redispersing. Silver organosols have been used to obtain metal films with an electrical conductivity of about 68 500 S/cm, which increases to 412 000 and 509 500 S/cm (87.8% of the electrical conductivity of bulk silver) after thermal treatment at 150 and 250°C, respectively. [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]

The detection and quantification of pharmaceutical compounds in various matrices, including environmental and biological samples, has received a great deal of attention due to their potential impact on human health and the environment. In this study, we present an electrochemical approach for the determination of nimesulide, a commonly used non-steroidal anti-inflammatory drug, in water supply, synthetic urine and drug samples. A 3D-printed electrochemical sensor was fabricated and modified by an electrochemical treatment in alkaline medium with KOH, followed by the electrodeposition of silver nanoparticles to improve its detection capabilities. The performance of the electrochemical sensor was evaluated by multiple techniques and a flow injection analysis with amperometric detection was applied for the quantification of nimesulide. The FIA-AMP system allowed for the efficient introduction of samples, promoting rapid analysis and minimizing memory effects. The sensor connected to the method showed good sensitivity (0.171 ± 0.002 µA L mol−1 cm−2) and improved stability (RSD < 7%) and its electrochemical responses were correlated with the concentration of nimesulide present in the samples tested, with recovery values in the 92 to 104% range. The method developed showed a good linear range from 5 to 25 µmol L−1 and a low detection limit of 0.81 µmol L−1, which makes it suitable for the quantitative analysis of nimesulide over a range of concentrations. The sensor applied to the determination of nimesulide offers a promising platform for the sensitive and selective detection of pharmaceutical compounds, contributing to greater safety and sustainability in these fields. [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]

Innovatively, four-layer, active biopolymer films based on furcellaran, chitosan and gelatin as well as active compounds (curcumin, capsaicin, AgNPs, montmorillonite and gelatin hydrolysate) were obtained. The films showed strong antioxidant effects. Adding active ingredients caused increased enthalpy change value (ΔH) and thermal stability. The potential application of the film was analysed by storing Atlantic salmon fillets in the material. The films showed an active effect. This effect was the strongest during the first 3 days of storage. Compared to the synthetic LDPE film, the active film showed a total 0.81 log/CFU lower microbial count on the 12th day of storage. Lipid oxidation was not delayed in the salmon. Nonetheless, the results indicate high applicative potential of the composites. [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]

Due to their tremendous industrial, environmental, and biological applications, research focusing on the synthesis and applications of silver nanoparticles (Ag NPs) has attracted increased interest from researchers over the past two decades. Their structural as well as textural properties can be easily tuned depending on the synthesis protocol utilized. Combustion synthesis has received increased attention as a one-pot route for the synthesis of a wide spectrum of nanomaterials. In this study, we present the results of synthesizing Ag NPs employing urea as a combustion fuel. The effect of the temperature of calcination on the formation and structural features of Ag NPs has been checked over the 400–700 °C temperature range. The characterization of the synthesized Ag NPs has been performed using XRD, SEM, TEM, and XPS techniques. It was found that Ag NPs, with a crystallite size of 40 nm, start to form at around 400 °C. Conducting the calcination at the 500–700 °C range results in the persistence of the obtained Ag NPs. Moreover, the obtained nanomaterials are characterized by a membrane-like morphology. The activity performance of the synthesized Ag NPs was examined for the hydrolysis of sodium borohydride (NaBH4) over a temperature range of 35–50 °C. Increasing the calcination temperature has led to a decrease in the activity of the Ag NPs during the NaBH4 hydrolysis. [ABSTRACT FROM AUTHOR]

The effective control of pathogenic bacteria is crucial in the restoration of periodontal tissue affected by periodontitis. Guided tissue regeneration (GTR) membranes are commonly used to aid in the repair of periodontal defects. Therefore, there is a clear advantage in developing antibacterial periodontal membranes that can effectively eliminate infections and promote tissue regeneration. This study aimed to create a collagen membrane with optimal content of silver nanoparticles (AgNPs) for effective antibacterial properties and minimal toxicity to mammalian cells. Ascorbic acid-reduced AgNPs were incorporated into collagen at the ratio of 0.5%, 1%, 2%, and 3% (based on total dry weight). Collagen/AgNPs hydrogels were compressed and freeze-dried to form membranes and then were characterized. Antibacterial activity was tested against Fusobacterium nucleatum and Enterococcus faecalis, and membrane cytocompatibility was accomplished on human gingival fibroblasts. Membranes with 2% and 3% AgNPs exhibited significant antibacterial activity, while 1% showed minimal activity and 0.5% and 0% showed none. HGF cells on the 3% AgNPs membrane had poor viability, proliferation, and adhesion, but 0%, 0.5%, 1%, and 2% AgNPs membranes showed desirable cellular behavior. In conclusion, the collagen membrane with 2% AgNPs demonstrated both antibacterial capacity and excellent cytocompatibility, making it a promising choice for periodontal treatments, especially in GTR approaches. [ABSTRACT FROM AUTHOR]

This research explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using Cassia occidentalis L. seed extract. Various analytical techniques, including UV–visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX), were employed for comprehensive characterization. The UV–visible spectra revealed a distinct peak at 425 nm, while the seed extract exhibited peaks at 220 and 248 nm, indicating the presence of polyphenols and phytochemicals. High-resolution TEM unveiled spherical and oval-shaped AgNPs with diameters ranging from 6.44 to 28.50 nm. The SEM exhibiting a spherical shape and a polydisperse nature, thus providing insights into the morphology of the AgNPs. EDX analysis confirmed the presence of silver atoms at 10.01% in the sample. XRD results unequivocally confirm the crystalline nature of the AgNPs suspension, thereby providing valuable insights into their structural characteristics and purity. The antioxidant properties of AgNPs, C. occidentalis seed extract, and butylated hydroxytoluene (BHT) were assessed, revealing IC50 values of 345, 500, and 434 μg/mL, respectively. Antibacterial evaluation against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli demonstrated heightened sensitivity of bacteria to AgNPs compared to AgNO3. Standard antibiotics, tetracycline, and ciprofloxacin, acting as positive controls, exhibited substantial antibacterial efficacy. The green-synthesized AgNPs displayed potent antibacterial activity, suggesting their potential as a viable alternative to conventional antibiotics for combating pathogenic bacterial infections. Furthermore, potential biomedical applications of AgNPs were thoroughly discussed. [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]

Background: Research on the use of silver nanoparticles in the context of diabetes mellitus has gained attention due to the unique properties of these nanoparticles, such as their antimicrobial, anti-inflammatory, and antioxidant characteristics. While the field is still in its early stages, several studies have explored the potential applications and effects of silver nanoparticles in managing diabetes. Diabetes mellitus, a global health concern marked by impaired insulin function and high blood glucose levels, has spurred innovative therapeutic investigations, including nanotechnology. Silver nanoparticles have emerged as promising candidates in this pursuit. This abstract provides an overview of current research on silver nanoparticles' application in managing diabetes mellitus, highlighting their therapeutic potential and mechanisms of action. With unique physicochemical properties like high surface area and bio-compatibility, silver nanoparticles are ideal for diverse biomedical applications. Recent studies show their ability to modulate key pathways in diabetes pathogenesis, enhancing insulin sensitivity, reducing oxidative stress, and supporting pancreatic beta-cell function. Their antimicrobial properties are particularly beneficial for diabetes patients prone to infections. Moreover, using silver nanoparticle-based carriers for anti-diabetic drugs improves drug bio-availability and reduces side effects, potentially enhancing conventional medication efficacy. However, addressing safety and toxicity concerns is crucial. Ongoing research focuses on optimizing nanoparticle size, shape, and surface modifications to enhance bio-compatibility and minimize adverse effects. Short conclusion: In conclusion, silver nanoparticles represent a novel and multifaceted approach in the management of diabetes mellitus. Their ability to target multiple facets of diabetes pathogenesis, including insulin resistance, oxidative stress, and inflammation, positions them as potential candidates for future therapeutic interventions. However, further research is warranted to elucidate their long-term safety profile and optimize their application in clinical settings. [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]