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

A colorimetric sensing platform based on carboxymethyl cellulose-silver nanoparticles (CMC-AgNPs) metallogel was proposed to monitor the temperature history and quality of perishable products stored at low temperature. The carboxymethyl cellulose (CMC) metallogel, fabricated in the presence of Ag+, incorporates ionic crosslinking of biopolymers, complexation between reactants, and subsequent in situ synthesis of AgNPs, which are designed to lead the color transition of metallogel from colorless to dark brown depending on temperature and time. The mechanical and structural properties of metallogels and AgNPs were characterized by rheology, XRD, and FT-IR. Color changes associated with temperature, time, and metal ion precursors were examined by UV–visible spectroscopy and colorimetry. The longer the exposure time to thermal stress condition such as room temperature (25 °C) or high temperature (60 °C), the deeper the color of metallogel. The CMC-AgNPs metallogel-based sensor provides an efficient, safe way to track temperature history and assess perishable products' quality, crucial for the safe distribution of food, vaccines, and medicines. This cost-effective and reliable visual sensor minimizes spoilage and health risks by enabling accurate temperature monitoring without the need for complicated equipment. [ABSTRACT FROM AUTHOR]

This study reports the green synthesis and characterization of silver nanoparticles (AgNPs) assisted with Cedrela odorata extracts and their antifungal efficacy against Fusarium circinatum, one of the most threatening pathogens in forest nurseries. Various extract volumes (1, 3, and 5 mL) of leaf and the bark of red cedar were tested. The nanoparticles were characterized using UV-Vis spectroscopy, transmission electron microscopy, and energy-dispersive spectroscopy of X-rays (EDS-TEM). Phytochemicals in the extracts were explored using Fourier transform infrared spectroscopy (FTIR). The results were analyzed using ANOVA and Tukey's tests with (p ≤ 0.05, 95%). Both leaves and bark extracts produced AgNPs, but the particles from bark extract (AgNPs-B) were smaller (19.80 ± 9.88 nm, λmax at 447 nm), and they were more stable than particles from leaf extract (AgNPs-L) because they showed a superficial plasmon resonance (SPR) over 12 months. Phenols and triterpenoids, associated with -OH, C=O, and –NH, were identified in the plant extracts that could act as reducing and capping agents. The AgNPs exhibited good antifungal activity because the inhibition diameter (11.38 ± 0.8 mm) observed for 800 mg AgNO3 L−1 was statistically similar to the inhibition diameter (10.7 ± 0.7 mm) at lower concentrations of particles (200 mg AgNPs L−1), and benzimidazole showed no fungus inhibition. Hence, it could be concluded that the bark extract performed better than the leaf extract. In conclusion, this study reports a new method for the synthesis of AgNPs assisted with cedar bark that exhibit a good antifungal activity against F. circinatum. [ABSTRACT FROM AUTHOR]

This research focuses on the application of nanocellulose-stabilized silver nanoparticles (AgNPs) as a colorimetric sensing probe for mercury (II) detection. For this purpose, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were employed with dual functions: a stabilizing agent and a dispersing matrix. The chemical and structural properties of the samples were analysed by various techniques such as XRD, FTIR, TEM and UV–Vis Spectroscopy. Due to different morphologies and surface functional groups in each type of nanocellulose, their effects on the AgNP formation as well as their response against mercury (II) ions were studied. It was discovered that the AgNPs stabilized by both types of nanocellulose can provide high sensitivity and selectivity towards mercury (II) ions. However, some interference caused by iron (III) ions was observed. This interference could be significantly reduced if the CNFs were employed during the AgNP preparation. Therefore, the advantage of using the CNFs as a stabilizing agent as well as a dispersing matrix will be discussed in detail. Furthermore, the possibility of fabrication into solid-state platforms (nanopapers) and response to mercury (II) ions will be demonstrated. [ABSTRACT FROM AUTHOR]

The production of antibacterial colored textiles using nanomaterials (NMs) has become an ideal goal from both a research and industrial perspective. In this study, the clean synthesis and characterization of silver nanoparticles (AgNPs) on polyamide fabrics were performed using mullein extract for the first time. Natural dyes were extracted from mullein leaves using an ultrasonic method, with an optimal amount of 15 g/L. The synthesized AgNPs in different ratios of mullein extract and Ag ions were analyzed (using UV–visible spectroscopy) and dynamic light scattering (DLS). It was found that AgNPs synthesized with a ratio of 1:4 of mullein extract: to Ag ions had a diameter of 85 nm. The active site groups of the synthesized AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR). Nylon fabrics dyed with different ratios of mullein extract and Ag ions exhibited acceptable color strength values (K/S) of 3.36. Furthermore, the reduction in bacterial growth for dyed fabrics improved with an increase in the ratio of Ag ions, with a 100% reduction observed for a sample dyed with mullein extract: Ag ions at a ratio of 1:4. Overall, this method offers a simple, low-cost, and compatible process with environment without the consumption of any chemicals to producing nylon with acceptable antibacterial and dyeing properties. [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]

Background: Recently, researchers are focusing on creating new tools to combat the antibiotic resistant bacteria and malignancy issues, which pose significant threats to humanity. Biosynthesized silver nanoparticles (AgNPs) are thought to be a potential solution to these issues. The biosynthesis method, known for its environmentally friendly and cost-effective characteristics, can produce small-sized AgNPs with antimicrobial and anticancer properties. In this study, AgNPs were bio-fabricated from the distilled water and methanolic extracts of Viburnum grandiflorum leaves. Physio-chemical characterization of the bio-fabricated AgNPs was conducted using UV-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis. Results: AgNPs produced from the methanol extract were smaller in size (12.28 nm) compared to those from the aqueous extract (17.77 nm). The bioengineered AgNPs exhibited a circular shape with a crystalline nature. These biosynthesized AgNPs demonstrated excellent bactericidal activity against both gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. Highest antibacterial activity was observed with the methanol extract against P. aeruginosa (14.66 ± 0.74 mm). AgNPs from the methanol extract also displayed the highest antioxidant activity, with an IC50 value of 188.00 ± 2.67 μg/mL against 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, AgNPs exhibited notable cytotoxic activity against Rhabdomyosarcoma cell line (RD cell) of human muscle cancer cell. The IC50 values calculated from the MTT assay were 26.28 ± 1.58 and 21.49 ± 1.44 μg/mL for AgNPs synthesized from aqueous and methanol extracts, respectively. Conclusion: The methanol extract of V. grandiflorum leaves demonstrates significant potential for synthesizing AgNPs with effective antibacterial, antioxidant, and anticancer actions, making them applicable in various biomedical applications. [ABSTRACT FROM AUTHOR]

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