Reduction Of Silver Ions Research Articles

Iron(III) edta-accelerated growth of gold/silver core/shell nanoparticles for wide-range colorimetric detection of hydrogen peroxide

As a naturally occurring reducing and oxidizing agent, hydrogen peroxide (H2O2) has a role in several biotic and abiotic processes. Hence, the onsite, precise, and rapid determination of H2O2 is crucial. Herein, we propose a method for colorimetric detection of H2O2 on the basis of hindered formation of gold/silver core/shell nanoparticles. We used ascorbic acid (AA) as the electron donor to reduce silver ions (Ag+) to be shelled around gold nanoparticles and iron(III) edta as an accelerator reactant. Upon reduction of Ag+, owing to the formation of core/shell nanoparticles, the color of the system changes from pink to yellow/orange in the spherical nanoparticles and from pink to purple/blue/green/yellow/orange in the nanorods. The nanorods distinguished color in a rainbow manner for higher concentrations of H2O2, and spherical nanoparticles were critical in the sensitive detection of lower concentrations of H2O2. H2O2 scavenges AA electrons and therefore inhibits core/shell formation and, consequently, restrains the system’s spectral shift and color change. This characteristic was exploited to measure different concentrations of H2O2. Under well-optimized conditions, various concentrations of H2O2 ranging from 1.0 to 50 µΜ have shown an acceptable linear relationship with different colors and, with a limit of detection (LOD) of 230 nM. Furthermore, various real samples were examined to confirm the practicality of our developed probe.

297. Comparative In Vitro Microbiologic Activity of Two Antimicrobial Intravenous Connectors

Abstract Background Intravenous (IV) connectors are ubiquitous access junctions in vascular access circuits. In accessing IV connectors (IVCs) for infusions, they become vulnerable to microbial contamination and colonization. Antimicrobial IVCs are treated with antimicrobial agents to resist microbial colonization. In this in vitro study, we compared the microbiologic efficacy of IVCs treated with silver and with a novel coating of Minocycline (M), Rifampin (R) and Chlorhexidine (C). MRC vs Silver Antimicrobial IV Connectors: 7-Day Microbiologic Challenge Test Colonization of MRSA, P. aeruginosa, and C. albicans on silver and MRC IVCs following 7 days of elution. Non-antimicrobial IVCs were used as positive controls. Data is presented as the median CFU/connector from six replicates; bars indicate the range. Methods M, R, and C were spray coated onto IVCs in sequential laminate layers to produce MRC IVCs. Commercially available silver IVCs were purchased (Antimicrobial Microclave Connector, ICU Medical Inc., San Clemente, CA). MRC and silver IVCs were immersed separately in tubes filled with 50% serum + 50% saline to simulate elution of the coatings. After 7 days elution (typical interval of use prior to replacement of IV connectors), eluted connectors were exposed to challenge inocula (5x105 CFU/mL) of key CLABSI clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa (PA), and Candida albicans (CA) for 24 hours at 37C. The number of viable colonizing microbes (CFU/connector) were enumerated by sonication, serial dilution, plating, and counting. Non-coated IVCs were positive controls. Log10 Reduction of MRC and Silver IV Connectors vs Positive Control Log10 reduction of the median number of CFU/connector recovered from six replicates following colonization of MRSA, P. aeruginosa, and C. albicans to silver IVCs and MRC IVCs. Results Figure 1 presents the median number of CFU/connector with range bars indicating the highest and lowest number of viable colonies recovered from six replicates after 7 days of elution and following 24-hour microbial challenges with MRSA, PA, and CA. Table 1 shows the median log reductions between positive control and coated connectors with p-values comparing MRC and silver IVCs calculated by Wilcoxon rank sum test. Conclusion The absence of microbial colonization of the MRC IVCs demonstrates the efficacy and durability of the novel MRC coating. The silver IVC was unable to fully eradicate biofilms of any of the tested pathogens. MRC IVCs were superior to silver IVCs (p< 0.05) for all pathogens tested. MRC-coated IVCs merit further testing in vitro and in vivo for their potential to prevent CLABSI. Disclosures All Authors: No reported disclosures

Silver Nanoparticles Produced Extracellularly by Sclerotinia sclerotiorum

Abstract Background: Sclerotinia sclerotiorum is one of the most important fungal species capable of manufacturing silver nanoparticles (AgNPs), which are formed through the biosynthesis process extracellular from silver nitrate solution (AgNo3) to the culture medium using a fungal cell filter; this study aims to explore the biosynthesis of AgNPs using S. sclerotiorum. Materials and Methods: AgNPs were produced by adding AgNo3 to the culture and then incubating for 72 h at 37°C. The nanoparticles were formed inside the cytoplasm and on the outer surface of the S. sclerotiorum fungus. These molecules were characterized using ultraviolet radiation, and the highest absorbance of AgNPs for S. sclerotiorum fungus was measured at 450 nm. AgNPs were also characterized using infrared analysis (Fourier transform infrared) and scanning electron microscope (SEM) to determine the size and crystal structure of these molecules. Results: S. sclerotiorum is a well-known phytopathogenic fungus with significant potential beyond its role as a plant pathogen. Various isolates of this fungus have diverse applications in agriculture, biotechnology, and nanotechnology. Notably, these isolates have demonstrated potential in reducing silver ions (Ag+) to (AgNPs), highlighting their promise in nanoparticle synthesis. In addition, the intensity of the absorption peak associated with the nanoparticles was found to increase over time, further supporting their potential for research and application. Conclusion: AgNPs produced by S. sclerotiorum is predominantly spherical, ranging from 5 to 50 nm, and are stabilized by a capping agent. These nanoparticles, found mainly on the fungal cell walls, likely result from fungal enzyme activity. Their antifungal properties are due to their interference with microbial DNA and disruption of metabolic processes, highlighting their potential as effective antifungal agents.

Encapsulation of Vecuronium and Rocuronium by Sugammadex Investigated by Surface-Enhanced Raman Spectroscopy.

Aiming toward a novel, noninvasive technique, with a real-time potential application in the monitoring of the complexation of steroidal neuromuscular blocker drugs Vecuronium (Vec) and Rocuronium (Roc) with sugammadex (SDX, medication for the reversal of neuromuscular blockade induced by Vec or Roc in general anesthesia), we developed proof-of-principle methodology based on surface-enhanced Raman spectroscopy (SERS). Silver nanoparticles prepared by the reduction of silver ions with hydroxylamine hydrochloride were used as SERS-active substrates, additionally aggregated with calcium nitrate as needed. The Vec and Roc SERS spectra were obtained within the biorelevant 5 × 10-7-1 × 10-4 M range, as well as the SERS of SDX, though the latter was observed only in the presence of the aggregating agent. SDX/drug complexes at a 1/1 molar ratio revealed significant spectral changes in the vibrational bands of the SDX glucose rings and the drug steroid rings, implying that the insertion of Vec and Roc molecules into the SDX cavity was not only driven by attractive electrostatic interactions between the positively charged cyclic unit of the drug and the negative carboxylate groups of cyclodextrin but also supported by hydrophobic interactions between the host cyclodextrin and the guest drug molecule. The observed changes in SERS signals are applicable in biorelevant conditions and support further studies of SDX/drug complexes in vivo.

Hydroxymethyl Lignin‐Capped Silver Nanoparticles: Antimicrobial and Hydrogen Peroxide‐Sensing Ability

AbstractLignin (Lg) fractionation overcomes the limitations of its heterogeneous nature. In this study, the effect of methanol fractionation on the thermal degradation, crystallinity, morphology, and chemical structure of lignin and its application in hydrogen peroxide sensing are investigated. Pristine Lg was separated into low‐molecular‐weight (LMwLg) and high‐molecular‐weight fractions (HMwLg), followed by modification to hydroxymethyl lignin (HmLg), which reduced silver ions in solution to silver nanoparticles (AgNPs). The functional groups, crystallinity, thermal profile, and morphology were then investigated using Fourier transform infrared spectroscopy, powder diffraction, thermal gravimetry, and scanning electron microscopy. LMwLg was found to be crystalline, highly hygroscopic, and had four thermal degradation stages, while HMwLg had several degradation stages and was amorphous. The sharp peaks in the LMwLg diffractogram were characteristic of sodium ions, while those in AgNPs‐HmLg were characteristic of AgNPs, as evidenced by the SPR peak at 428 nm whose intensity decreased in the presence of hydrogen peroxide. Moreover, AgNPs‐HmLg exhibited higher inhibitory activity toward Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis with inhibition zones of 10.67 ± 0.58, 11.50 ± 0.00, 10.33 ± 0.58, and 8.33 ± 0.57 cm as compared to pristine lignin. In conclusion, AgNPs‐HmLg detected the presence of hydrogen peroxide in solution and inhibited the growth of selected Gram‐positive and Gram‐negative bacteria.

Mono‐disperse submicron silver powder for conductive elastomer

AbstractThe synthesis of superfine silver powder with good dispersity is of great significance for accelerating the development of high‐end electronics and photovoltaic products. Herein, a kind of quasi‐spherical submicron silver powder prepared by the introduction of gelatin during silver ions reduction is reported. The optimal scheme is determined that the initial pH of gelatin solution is 3 and the mass of gelatin (Mw 50,000—70,000) is 10% of silver nitrate, leading to a mono‐disperse silver powder with regular morphology and average particle size of 0.5 µm. In addition, the prepared silver powder can be further combined with polydimethylsiloxane (PDMS) to form a stretchable conductive elastomer (PDMS/Ag elastomer). In unstretched state, the minimum sheet resistance of the elastomer can reach 66 Ω/□ without annealing treatment. Even when the elongation reaches 100%, it still exhibits good conductivity with a sheet resistance of only 13 kΩ/□. The comprehensive performance, mainly referring to stretching and conductivity, is comparable to that of some flexible conductive materials involving silver nanowire or nanocarbon. Thus, this study will demonstrate a new class of silver powder with a potential in flexible electronics.

The optical and electrochemical characteristics of silver nanoparticles, besides antibacterial and antifungal properties using crocus sativus.l petal

The manufacture of silver nanoparticles using plant extract is a simple, worthwhile, and ecologically friendly method. We present the use of in this study Crocus sativus .L petal extract is being used to create environmentally friendly nanoparticles. In the green approach, UV-Vis spectroscopy is utilised to characterise and confirm the presence of silver nanoparticles containing reduced silver ions. The XRD confirms the silver nanoparticles' crystalline structure formed in this process. Scanning electron microscopy reveals predominantly spherical and triangular shapes of the nanoparticles, with sizes ranging from 20 to 45 nm. To examine electrochemical properties, cyclic voltammetry and electrochemical impedance studies were utilised. Consequently, when subjected to the disc diffusion method, the synthesized silver nanoparticles exhibit enhanced antibacterial activity against various strains such as Pseudomonas aeruginosa, Proteus vulgaris, Enterococcus faecalis, Streptococcus Mutans, Enterococcus aeruginosa, and Bacillus subtilis.

In Situ Growth of Silver Nanoparticles into Reducing-End Carbohydrate-Based Supramolecular Hydrogels for Antimicrobial Applications.

Hydrogels with antibacterial activities have the potential for many biomedical applications, such as wound healing, because of their capacity to maintain a moist environment and prevent infections. In this work, an ultrasound-induced supramolecular hydrogel consisting of easily accessible reducing-end-free glucosaminylbarbiturate-based hydrogelators that serve the in situ fabrication of silver nanoparticles (AgNPs), excluding the addition of any external reducing or stabilizing agents, has been developed. The innovative synthetic approach relied on the use of N,N'-disubstituted barbituric acid derivatives as a versatile chemical platform that site-selectively reacted with the amino function of glucosamine. A series of glucosaminylbarbiturate were synthesized, and we identified one carbohydrate-based hydrogelator that produced a thixotropic supramolecular hydrogel after ultrasound-mediated breaking of an intralocked hydrogen bond. AgNPs@hydrogels were prepared through in situ reduction of silver ions mediated by the reducing properties of carbohydrates. The AgNPs@hydrogel composite revealed good antimicrobial properties toward both Gram-positive and Gram-negative bacteria. These findings contribute to the development of carbohydrate-based supramolecular hydrogels and make them promising efficient and safe soft materials for antimicrobial therapy.

Biofabrication of rhamnolipid biosurfactant for nanoparticle stabilization and chitosan immobilized lipase: A green detergent additive

AbstractBiosurfactants prevent agglomeration of nanoparticles by reducing the surface tension and offer stability over time by forming a stable layer on the surface of nanoparticles. The current study focuses on the biosynthesis of silver nanoparticles (SNP) coated with a rhamnolipid biosurfactant (BS) and its use as an additive in fabric cleaning detergent. Rhamnolipids were extracted from a Pseudomonas aeruginosa strain, Pa84, that was isolated from a halophilic environment, Sambhar Salt Lake, Rajasthan, India. The reduction of silver ions was achieved by the rhamnolipid‐coated SNP (BS‐SNP). BS, SNP, and BS‐SNP demonstrated antibacterial efficacy against a variety of microorganisms. Lipase, present in the crude biosurfactant, was immobilized on modified chitosan microbeads (Ch‐BS‐SNP) and used for washing fabrics. The conjugate was found to be effective as a laundry detergent additive. The immobilized lipase showed high relative activity ranging from 66% to 110% and performed better than free lipase or standards. Our results highlight a potential claim for a commercially viable laundry detergent additive.

Green-synthesized silver nanoparticles induced apoptotic cell death in CACO2 cancer cells by activating MLH1 gene expression

MLH1 (Mult homolog1) gene is the main element of Multlα heterodimer and plays a role in the repair of base-base mismatches and deletion and addition loops. When the MLH1 protein is not present, the number of errors that remain unrepaired increases, and this can lead to the formation of tumors in the body. Colorectal cancer is the third most common type of cancer in terms of incidence and the third type of cancer in terms of mortality worldwide. In this regard, the present study was conducted with the aim of investigating the effect of biological silver nanoparticles with anticancer properties and MLH1 gene expression on cancer cell samples of people with colorectal cancer. In this study, the green synthesis of silver nanoparticles was carried out by precipitation method with reduction of silver ions by leaf and flower extract of Moringa oleifera plant. Then, silver nanoparticles were confirmed using UV-visible spectroscopy, transmission and scanning electron microscopy. The cytotoxic effects of nanoparticles on cells were evaluated by MTT colorimetric method within 42 h. After RNA extraction of treated cells, cDNA synthesis and primers were designed by the Exon-Exon Junction method and the Real-time Polymerase test for MLH1 and Beta-actin genes was repeated three times. The final analysis of the results was done using Graphpad Prism and Rest 2009 software. The presence of a peak at the wavelength of 234 nm for the synthesized silver nanoparticles was confirmed by ultraviolet-visible spectroscopic analysis. The morphological study on the size and shape of the silver nanoparticles showed that the nanoparticles are spherical and have a size between 40 and 34 nanometers in diameter. The leaf extract typically produces smaller, more uniform particles than the flower extract. The Green-Synthesized Silver Nanoparticles of leaf extract were used to evaluation of induced Apoptotic Cell Death in CACO2 Cancer Cells by Activating MLH1 Gene Expression. MTT results showed that the anti-proliferative effect of nanoparticles depends on the concentration of synthesized silver nanoparticles. The treatment of MLH1 cancer cell line and normal with synthesized nanoparticles at a concentration of 0.44 micrograms per ml for 42 h showed the effects of cell toxicity. The percentage of cancer cell death under the influence of quercetin present in Moringa green bio-particles depends on the concentration and time, and this difference is statistically significant compared to the control group (P < 0.05). So that the lethal dose of the extract for 50% survival IC50 in a period of 48 h for intestinal cancer cells was equal to 21 μg/ml, and the expression ratio of the MLH1 gene in the tumor tissue to the adjacent healthy tissue has increased (P ≤ 0.05).

Toxic Dye Degradation Employing Phoenix dactylifera Seed Extract for the Green Synthesis of Silver Nanoparticles: Characterization and Application.

This research highlights the facile green synthesis of silver nanoparticles (AgNPs) using Phoenix dactylifera seed extracts and its photocatalytic application for the degradation of toxic dyes. The AgNPs synthesis was confirmed by the appearance of its representative absorption peak at 416 nm in UV-visible absorption spectroscopy. Moreover, the reduction of silver ions to Ag was justified through Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction pattern revealed crystalline AgNPs structure with particle size ranging from 5 to 15 nm calculated using the Debye-Scherrer equation. The rectangular-like structural morphology of synthesized AgNPs was observed in scanning electron micrographs. The as-synthesized AgNPs demonstrated higher photocatalytic activity for the degradation of malachite green (MG) and congo red (CR) followed by methylene blue (MB), and crystal violet (CV) under UV irradiation. In addition, rate constant (k) and percentage degradation were also calculated. The present study presents a facile green synthesis pathway and its potentially successful manipulation in the reduction of toxic dyes under the illumination of UV-light.

Cytotoxic activity of silver nanoparticles prepared by eco-friendly synthesis using Lythrum salicaria extract on breast cancer cells.

Metal nanoparticles (NPs) have widely been investigated due to their several applications in therapeutic activities. The current investigation highlights the cytotoxic effects of the eco-friendly phytosynthesis route for silver nanoparticles using Lythrum salicaria (L. salicaria) extract (AgNPs-LS). The change in color from colorless to brown confirmed the reduction of silver ions to AgNPs. x-ray diffraction (XRD) analysis demonstrated high crystallinity. The surface morphology of AgNPs-LS was spherical, and their average sizes were 50nm. energy-dispersive x-ray analysis (EDAX) confirmed that silver was the predominant component, indicating the involvement of L. salicaria plant extract in the green synthesis process. In vitro dimethyl thiazolyl tetrazolium bromide (MTT) assay showed significant cytotoxicity of AgNPs-LS against MCF7 cells, with an IC50 of 113µg mL- 1. In contrast, AgNPs-LS showed minimal cytotoxicity to HEK293 cells (IC50: 254µg mL- 1), demonstrating a higher sensitivity of cancer cells to AgNPs-LS. Moreover, AgNPs-LS resulted in MCF7 cells producing reactive oxygen species (ROS) and undergoing cell cycle arrest at the G2/M phase, serving as barriers to the proliferation of cancer cells. Annexin V fluorescein isothiocyanate (FITC) assays and fluorescence microscopy confirmed the induction of apoptosis in MCF7 cells by AgNPs-LS. Gene expression analysis revealed upregulated pro-apoptotic genes (Bax, p53, caspase-3, and caspase-9) and downregulated an anti-apoptotic gene (Bcl2) in michigan cancer foundation7 (MCF7) cells treated with AgNPs-LS. These results indicate that AgNPs-LS induced apoptosis via the intrinsic pathway (mitochondrial-mediated mechanism) and involved p53-dependent regulation. The current study results implied that AgNPs-LS fabricated by a bio-green approach could be helpful to the future of nanomedicine.

Exploring the efficacy of Pongamia pinnata-induced silver nanoflowers for efficient adsorptive degradation of malachite green dye

In this study, silver nanoflowers were synthesized due to catalytic reduction of silver ions by phytochemicals of Pongamia pinnata seed cake extract (PSCAgNPs) in 24 h and subsequently used for removal of malachite green (MLG) dye. PSCAgNPs were characterized by UV–Visible spectrophotometry, scanning electron microscopy (SEM), energy-dispersive X ray spectroscopy (EDAX), Fourier Transformed Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD) and BET analysis. The synthesized PSCAgNPs were floral in appearance, of size 18.82—23.70 nm with SPR at 430 nm and crystalline in nature. PSCAgNPs adsorbed 90.01 ± 0.17% of 50 mg/L MLG post one factor at a time analysis. Adsorption followed pseudo-second-order kinetics (k1 = 2.5E-03 g/mg.h), was observed as unilayer chemisorption as the equilibrium data best fitted Langmuir isotherm (Langmuir coefficient = 0.1724 L/mg, R2 = 0.9945). Upon interaction of MLG by PSCAgNPs, hydroxylation of MLG leads to formation of MLG carbinol in the first stage of adsorptive degradation, as evident from LCMS chromatograms.Graphical

Phytofabricated silver nanoparticles derived from Leea crispa leaf extract: Antituberculosis and anticancer activities

Aqueous extracts of Leea crispa used for producing silver nanoparticles (AgNPs) with the supplementation of the external capping substance, were determined by UV-Visible spectroscopy. The synthesized nanoparticles were examined for their antituberculosis and anticancer activities. The presence of phytoconstituents available for reducing silver ions and to form the AgNPs was confirmed using FTIR analysis. The XRD and TEM examination validated the AgNPs’ spherical particle shape and size of 15 to 85 nm and their face-centered cubic crystal form. Additionally, the FTIR spectrum revealed variation in the band values in the range 1384.0 to 3419.4 cm-1, respectively, and the EDX noted a strong band at 3 keV induced the presence of metallic silver. The AgNPs exhibited comparatively potential anti-tuberculosis activity (0.2 to 100 µg/mL) respectively. Alternatively, various doses of AgNPs, 12.5 to 400 µg/mL documented considerable activity towards the human breast cancer cell lines. The percentage of cell viability increased at 12.5g/mL and declined at 400 ng/mL concentrations of AgNPs solution. The AgNPs synthesized from L. crispa exhibited potential activity against life-threatening tuberculosis and cancer cells.

Metallization process optimization of HIT solar cell for high current density and silver reduction

Metallization process optimization of HIT solar cell for high current density and silver reduction

Antibacterial and Photocatalytic Applications of Silver Nanoparticles Synthesized from Lacticaseibacillus rhamnosus.

The biosynthesis of silver nanoparticles (AgNPs) presents an innovative and sustainable approach in nanotechnology with promising applications in fields such as medicine, food safety, and pharmacology. In this study, AgNPs were successfully synthesized using the probiotic strain Lacticaseibacillus rhamnosus (BCRC16000), addressing challenges related to stability, biocompatibility, and scalability that are common in conventional nanoparticle production methods. The formation of AgNPs was indicated by a color change from yellow to brown, and UV-visible spectrophotometry confirmed their presence with a characteristic absorption peak at 443 nm. Furthermore, Fourier transform infrared (FTIR) spectroscopy revealed the involvement of biomolecules in reducing silver ions, which suggests their role in stabilizing the nanoparticles. In addition, field emission scanning electron microscopy (FE-SEM) showed significant morphological and structural changes. At the same time, dynamic light scattering (DLS) and zeta potential analyses provided valuable insights such as average size (199.7 nm), distribution, and stability, reporting a polydispersity index of 0.239 and a surface charge of -36.3 mV. Notably, the AgNPs demonstrated strong antibacterial activity and photocatalytic efficiency, underscoring their potential for environmental and biomedical applications. Therefore, this study highlights the effectiveness of Lacticaseibacillus rhamnosus in the biosynthesis of AgNPs, offering valuable antibacterial and photocatalytic properties with significant industrial and scientific implications.

Eco-friendly synthesis of silver nanoparticles by Trigonella foenum-graecum: formulations, characterizations, and application in wound healing

Background Due to the toxicity and serious side effects of chemical incorporated in topical dosage form used for treatment of wound healing, there is a need to use natural preparation as wound healing preparation. Aims Seeds of Trigonella foenum-graecum (TFG) are used to synthesize eco-friendly silver nanoparticles (SNPs) in an appropriate way to heal wounds. Methods To synthesize SNPs, TFG was incubated with AgNO3 to produce SNP-TFG. The obtained SNP-TFG was characterized for their wavelength, size and ζ-potential, surface morphology, and yield production. Then, SNP-TFG was formulated as a topical cream (O/W), characterized, and applied to the rats’ groups to examine its wound-healing activity. Finally, a skin biopsy was performed to assess all rats’ immunostaining and histopathological (HP) alterations in skin lesions on days 3, 7, 10, and 14. Results The prepared SNP-TFG showed non-aggregated nano-formulation, with a λmax of 396 nm. SNP-TFG recorded a size of 43.65 ± 2.1 nm, a charge of −15.03 ± 3.2 mV, and showed yield of 52.61 ± 1.41% while the release was continued for more than 12 h. During the biosynthesis process, the compounds present in TFG are capable of reducing silver ions (Ag+) to form SNPs. SNP-TFG cream showed a pH nearly equal to the skin’s pH, with suitable viscosity and homogeneity and an apparent permeability of 0.009 ± 0.001. Further, the HP of the SNP-TFG showed a substantial reduction in wound mass, wound granulation tissue growth enhancement, and epidermal re-epithelialization (proliferation) compared to the control group. Conclusion The obtained SNP-TFG is considered a novel skin wound-healing natural and eco-friendly nano-formulation.

Precise control of silver nanoplate dimensions and optical properties via pH, EDTA and AMP mediated synthesis

We present a seed-mediated synthesis method for producing silver nanoplates (AgNPTs) with customizable size and thickness, ensuring high yield and precise optical properties. This approach leverages ethylenediaminetetraacetic acid (EDTA) as a key component in the synthesis process, utilizing small single-crystal silver seeds. The interaction between Ag+ ions and EDTA at varying pH levels dynamically regulates silver complexation and reduction kinetics during seed overgrowth, leading to the formation of truncated nanoplates with superior optical responses. By adjusting the pH within the range of 8-10.5, we can manipulate the growth of the nanoplates, enabling a flexible optical response ranging from 519 to 1006nm due to changes in their size and thickness. Additionally, nanoplate overgrowth extends plasmon resonance up to approximately 2000nm. The incorporation of Adenosine 5' monophosphate (AMP) not only enhances nanoplate stability but also allows for precise thickness adjustment independent of growth kinetics. This method provides a systematic approach to tailor nanoplate morphology and optical properties with unprecedented precision. The role of EDTA is attributed to its complexation ability with Ag+ and its assistance in facet evolution, supported by density functional theory (DFT) simulations of surface energies modified by EDTA adsorption. Furthermore, DFT calculations confirm that AMP can further modify the surface energies of different facets, enabling precise thickness control.

Aqueous dispersions of ‘green’ silver nanoparticles for eco-applications: Synthesis, structure and biosafety

Aqueous dispersions of ‘green’ silver nanoparticles for eco-applications: Synthesis, structure and biosafety

Antimicrobial Activity of Amino-Modified Cellulose Nanofibrils Decorated with Silver Nanoparticles.

Silver nanoparticles (Ag NPs) conjugated with amino-functionalized cellulose nanofibrils (NH2-CNFs) were in situ-prepared by reducing silver ions with free amino groups from NH2-CNFs. The spectroscopy and transmission electron microscopy measurements confirmed the presence of non-agglomerated nanometer-in-size Ag NPs within micrometer-large NH2-CNFs of high (20 wt.-%) content. Although the consumption of amino groups during the formation of Ag NPs lowers the ζ-potential and surface charge of prepared inorganic-organic hybrids (from +31.3 to +19.9 mV and from 2.4 to 1.0 mmol/g at pH 7, respectively), their values are sufficiently positive to ensure electrostatic interaction with negatively charged cell walls of pathogens in acidic and slightly (up to pH ~8.5) alkaline solutions. The antimicrobial activity of hybrid microparticles against various pathogens (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans) is comparable with pristine NH2-CNFs. However, a long-timescale use of hybrids ensures the slow and controlled release of Ag+ ions to surrounding media (less than 1.0 wt.-% for one month).