Stable Silver Nanoparticles Research Articles

Enhanced adsorption of toluene using nano silver-modified activated carbon derived from Ricinodendron heudolitii shells: A comparative study"

Considering the risk of toluene exposure in water resources, researchers have been prompted to conduct experiments to remove them from aqueous solutions. This study investigates the use of Ricinodendron Heudolitii shells as a precursor for extracting an adsorbent (activated carbon) through chemical activation with phosphoric acid (H3PO4). The obtained activated carbon was then modified with Quercetagetin stabilized silver nanoparticles (Qtg-Ag/AC), and characterized for thermogravimetric analysis (TGA), Fourier-transformed infrared spectroscopy (FTIR), diffraction light scattering, Powder XRD, and scanning electron microscopy (SEM/EDX). The adsorption characteristics such as kinetics, mechanism and isotherms of toluene were studied. The kinetic data were analyzed using a pseudo-first-order, pseudo-second-order kinetic equation elovick and intraparticle diffusion model. The pseudo-first-order and pseudo-second-order kinetic model describes experimental data better than elovich and intraparticle kinetic model. The results show that Qtg-Ag/AC exhibits superior adsorption capacity (39.352 mg g−1) compared to AC (30.093 mg g−1). Langmuir, Freundlich and Tenkim model for AC and Qtg-Ag/AC described the equilibrium data better. In order to determine the best-fit kinetic model for each system, two error analysis methods, namely, chi-square (χ2) and residual mean squared error (RMSE) were used to evaluate the data. The outcomes of the study demonstrate that our modified (Qtg-Ag/AC) can be a good prototype for the adsorption of toluene from wastewater.

PH and NaCl Optimisation to Improve the Stability of Gold and Silver Nanoparticles' Anti-Zearalenone Antibody Conjugates for Immunochromatographic Assay.

The aim of this research is to define optimal conditions to improve the stability of gold and silver nanoparticles' anti-zearalenone antibody conjugates for their utilisation in lateral flow immunochromatographic assay (LFIA). The Turkevich-Frens method was used to synthesise gold nanoparticles (AuNPs), which were between 10 and 110 nm in diameter. Silver nanoparticles (AgNPs) with a size distribution of 2.5 to 100 nm were synthesised using sodium borohydride as a reducing agent. The onset of AuNP and AgNP aggregation occurred at 150 mM and 80 mM NaCl concentrations, respectively. Stable Au and Ag nanoparticle-antibody conjugates were achieved at 1.2 mM of K2CO3 concentration, which corresponds to the pH value of ≈7. Lastly, the highest degree of conjugation between Au and Ag nanoparticles and anti-zearalenone antibodies was at 4 and 6 µg/mL of antibody concentrations. The optimisation of the conjugation conditions can contribute to better stability of nanoparticles and their antibody conjugate and can improve the reproducibility of results of bioreporter molecules in biosensing lateral flow devices.

Synthesis of Silver Nanoparticles Using Hydroalcoholic Extract of Sambucus Nigra and Lavandula Angustifolia

Abstract Technique development for getting environmentally friendly nanomaterials was the paper's main goal. Spectroscopic techniques were utilized to characterize the plant extracts used in this work (UV-Vis, FTIR and Raman). In this case, plants from the Valea Voievozilor was processed in a dry state, was used at the ideal moment and at the plant's peak maturation period. Several analytical techniques (UV-Vis, FTIR, Raman analysis) have been used to analyze the nanoparticles (Ag) created with the aid of these plant extracts. Both the bioreduction of silver ions (Ag+ to Ag0) and the stability of silver nanoparticles are caused by the bioactive chemicals found in plant materials.

Green biosynthesis of stable silver nanoparticles bound with macaranga indica plant extracts for the purification of drinking water

Plant-assisted green biosynthesis of silver nanoparticles (NPs) has become the most powerful technique to prepare stable NPs. Macaranga indica is a medicinal plant widely available in the western ghats. It has verities of medical properties like antibacterial, antioxidant, antidiabetic, cytotoxicity, and antidysentery and is commonly used in the traditional medicine system. This plant also contains polyphenols, flavonoids, and other plant constituents. Here, in this study, macaranga indicia leaf extract is used as a capping agent for the synthesis of silver NPs by using the microwave irradiation technique. Synthesized NPs are characterized by using Uv-Vis Spectra, XRD, EDX, FESEM, and FTIR. Interpretation of characterization data reveals that synthesized NPs are in a spherical shape, monodispersed, and have particles the size of ~15-20 nm. These bicapped silver NPs have shown potential thermotolerant bacterial inhibition activity and are also efficient in methylene blue dye removal and hence can be used in the purification process of drinking water at its source.

Определение теплофизических свойств и функции радиального распределения наночастицы серебра с применением численных методов

The performance of microelectronic devices based on silver nanostructures depends on their thermophysical properties. Therefore, it is important to study the thermophysical properties of silver nanostructures depending on their size and structure. In this work, the thermal stability of spherical silver nanoparticles was studied using computer simulation by the molecular dynamics method. In the course of this work, the temperature dependences of the potential part of the specific internal energy of silver nanoparticles were obtained with a change in the size of the nanoparticle for various potentials corresponding to the embedded atom” method. Using numerical data processing methods, the temperatures of the beginning and end of melting were determined. Also, size dependences of the melting temperature and specific heat of fusion of silver nanoparticles were plotted and analyzed for different potentials of the “embedded atom”. Potentials that provide the best agreement with the tabular values of the macroscopic melting temperature and specific heat of fusion were determined. In addition, the radial distribution function for a silver nanoparticle was constructed and analyzed at different temperatures and for different sizes of the nanoparticle.

SYSTEMATIC LITERATUR REVIEW: SYNTHESIS OF SILVER NANOPARTICLES (AgNPs) USING SECONDARY METABOLITES OF FRUIT PEEL EXTRACT

The synthesis of silver nanoparticles (AgNPs) using secondary metabolites of biological materials is a simple, cost-effective, and environmentally friendly method compared to physical synthesis methods. The secondary metabolites of the fruit peel extract can be used to synthesize AgNPs. Researchers chose experimental research articles with the theme of silver nanoparticle synthesis using fruit peels for review and selected journals published from 2018 to 2022 from web searches PubMed, Google Schoolar, Scopus, and ScienceDirect. The researchers screened and selected 28 articles according to the inclusion and exclusion criteria. The synthesis of AgNPs using fruit peel extracts can produce stable nanosized AgNPs. Silver nanoparticles synthesized using fruit peels showed stable silver nanoparticle synthesis results in terms of zeta potential and polydispersity index (PDI) values and obtained an average size of 2–200 nm with a spherical shape. Keywords: Silver Nanoparticles, Fruit Peel Extract, Antibacterial agent

Utilization of aqueous broccoli florets extract for green synthesis and characterization of silver nanoparticles, with potential biological applications

The process of creating nanoparticles using chemicals is not eco-friendly. However, a more environmentally conscious approach known as green chemistry, which involves using vegetable-mediated nanoparticle production, combines nanotechnology with biotechnology. In this study, the researchers aimed to assess the effectiveness of the green chemistry technique in producing silver nanoparticles using an liquid extract from broccoli florets (Brassica oleracea) under ideal environment. The successful production of silver nanoparticles was achieved through silver nitrate (AgNO₃) biological reduction with the help of an aqueous broccoli florets extract at a slightly acidic pH of 6–7. The silver nanoparticles occurrence was shown by a change of color that moved from colorless to reddish-brown. To characterize the green-produced nanoparticles, various analytical techniques such as Ultraviolet–Visible Spectroscopy (UV-VIS), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDAX) were employed. The antioxidant properties of the formed silver nanoparticles (AgNPs) were examined in vitro using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) tests. Additionally, the antibacterial properties of AgNPs against various pathogenic bacteria was evaluated. The reduction procedure was easy and simple manageable, with UV–Vis spectroscopy indicating the surface plasmon resonance (SPR) presence at 425 nm. FTIR was utilized to identify active chemical groups in the biomass before and after reduction. SEM and X-ray diffraction analyses indicated that the silver nanoparticles had an average the size of individual particles of 33 nm and exhibited a face-centered cubic (FCC) structure. EDAX analysis confirmed the occurrence of elemental silver in the nanoparticles. The study demonstrated that the biosynthesis of AgNPs led to significant variations in antioxidant activity, which was dose-dependent and showed a similar pattern to the testing of the scarfing action of the ascorbic acid against free radicals using DPPH and FRAP. The AgNPs also dispalyed firm deep-spectrum antibacterial action observed against the tested pathogenic bacteria, outperforming certain medications. Interestingly, the silver nanoparticles remained stable at ambient temperature for 25 days without precipitation, retaining their antioxidant and antibacterial properties. In conclusion, the research findings suggest that an aqueous extract of fresh broccoli florets can serve as a viable and environmentally friendly method for producing stable silver nanoparticles with beneficial antioxidant and antibacterial characteristics.

Comparative analysis of polydopamine and casein coated Arabic gum stabilized silver nanoparticles for enhanced antimicrobial activity of quercitrin

This study focuses on the green synthesis of silver nanoparticle (Ag NPs) stabilized by gum Arabic as a nanocarrier for quercitrin which was subsequently modified with casein (Cs) and polydopamine (PDA) to improve its antimicrobial potential against S. aureus. The developed gum Arabic based AgNPs (GA-Ag NPs) exhibited 67.31 ± 0.01% encapsulation efficiency for quercitrin. Furthermore, the synthesized AgNPs were characterized using various techniques including UV–visible spectroscopy, Dynamic light scattering (DLS), FT-IR (Fourier transform infrared spectroscopy), and AFM (Atomic force microscopy). Finally, antibacterial activity of synthesized AgNPs was investigated against resistant and sensitive S. aureus strains. Results demonstrated the spherical shape morphology and nano range particle size for Cs and PDA modified quercetrin loaded GA-Ag NPs. Both the systems exhibited sustain drug release profile with maximum release of more than 70%. Furthermore, antibacterial study revealed that the MIC and MBIC of quercetrin significantly decreased after being functionalized with Cs and PDA. Results were further confirmed by analyzing the morphological changes in the bacterial cells utilizing AFM. However, the results were more obvious for PDA functionalized quercetrin loaded GA-AgNPs upon comparison with Cs modified system. Hence, the developed PDA functionalized NPs can serve as efficient delivery vehicles over the existing systems for increasing the bactericidal potentials of quercitrin.

Influence of poly(butyl acrylate-co-methacrylic acid) stabilized silver nanoparticles on mechanical and antibacterial properties of peroxide prevulcanized natural rubber

Colloidal poly(butyl acrylate-co-methacrylic acid) (P(BA-co-MAA)) particles were synthesized by surfactant-free emulsion polymerization. The polymeric particles were then mixed with natural rubber latex which was further prepared as peroxide prevulcanized natural rubber-poly(butyl acrylate-co-methacrylic acid)/silver (PPNR-P(BA-co-MAA)/Ag) nanocomposites. UV–visible (UV–vis) spectra and transmission electron microscope (TEM) images indicated the octahedral shape of AgNPs in the nanocomposite films. The presence of P(BA-co-MAA) in the nanocomposite films increased tensile strength compared to films without P(BA-co-MAA). The highest enhancement of mechanical properties of the nanocomposites was obtained with 10,000 and 5000 ppm of P(BA-co-MAA) and AgNO3, respectively. The PPNR-P(BA-co-MAA)/Ag films exhibited a bactericidal effect against E. coli and S. aureus. The successful bacterial reduction results corresponded to Ag+ released from the nanocomposite films and the presence of Ca2+ from a coagulant in the dipping process.

Mixed Micellization of Promazine Hydrochloride with Cholinium‐Based Anionic Surface Active Ionic Liquids and their Potential Application for the Synthesis of Silver Nanoparticles

AbstractThis work is aimed to study the interaction of an amphiphilic drug, promazine hydrochloride (PMZ) and two anionic surface active ionic liquids (SAILs), cholinium laurylsarcosinate [Cho][Sar] and cholinium deoxycholate [Cho][Doc] using conductivity, UV‐visible spectroscopy and fluorescence techniques. The results obtained by all three techniques indicated non‐ideal behavior and synergistic interactions between the PMZ drug and SAIL mixed systems. Further, the drug‐SAIL mixtures were used to stabilize silver nanoparticles (Ag NPs) in aqueous solution. The results of UV‐visible spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that PMZ and SAILs had strong electrostatic and hydrophobic interactions which played a significant role in the stabilization of Ag NPs. The morphological analysis of the Ag NPs showed the formation of various types of aggregates controlled by the internal packing of PMZ‐[Cho][Sar]/[Cho][Doc] mixed systems. These drug‐SAIL based NPs could be used in separation and synthesis applications in nanotechnology by altering the structure of drugs and SAILs.

Drug-Delivery Silver Nanoparticles: A New Perspective for Phenindione as an Anticoagulant.

Anticoagulants prevent the blood from developing the coagulation process, which is the primary cause of death in thromboembolic illnesses. Phenindione (PID) is a well-known anticoagulant that is rarely employed because it totally prevents coagulation, which can be a life-threatening complication. The goal of the current study is to synthesize drug-loaded Ag NPs to slow down the coagulation process. Methods: A rapid synthesis and stabilization of silver nanoparticles as drug-delivery systems for phenindione (PID) were applied for the first time. Results: Several methods are used to determine the size of the resulting Ag NPs. Additionally, the drug-release capabilities of Ag NPs were established. Density functional theory (DFT) calculations were performed for the first time to indicate the nature of the interaction between PID and nanostructures. DFT findings supported that galactose-loaded nanostructure could be a proper delivery system for phenindione. The drug-loaded Ag NPs were characterized in vitro for their antimicrobial, cytotoxic, and anticoagulant activities, and ex vivo for spasmolytic activity. The obtained data confirmed the drug-release experiments. Drug-loaded Ag NPs showed that prothrombin time (PT, sec) and activated partial thromboplastin time (APTT, sec) are approximately 1.5 times longer than the normal values, while PID itself stopped coagulation at all. This can make the PID-loaded Ag NPs better therapeutic anticoagulants. PID was compared to PID-loaded Ag NPs in antimicrobial, spasmolytic activity, and cytotoxicity. All the experiments confirmed the drug-release results.

Sustainable augmentation in lyocell knitted sportswear functionality by in-situ synthesis of biogenetically reduced silver nanoparticles

Metal nanoparticles, well-known for their enhanced quality characteristics, are prepared by many chemical and physical methods. The biosynthesis method for preparing nano-particle becomes more popular due to increased environmental safety concerns and the complicity involved in other methods. Its superiority over other methods is evidenced by the fact that it is produced in aqueous solution at room temperature without the use of additives or accelerating agents, and without any significant energy or waste inputs. The nano-edged antibacterial fabric if developed using green technology and in a single step rather than following a multi-stepped process can set up milestones for the commercial variability of the nanocomposite. The present investigation deals with the development of ecological, economical, and highly stable silver nanoparticles (AgNPs) synthesized within the polymer matrix of Lyocell knitted fabric using the green route. Azadirachta Indica leaves extract was used as a stabilizing agent. The lyocell fabric augmented with silver nanoparticles was characterized for its surface morphology by scanning electronic microscopy (SEM) technique. The uniform distribution of AgNPs was seen from the SEM image. The chemical structure of the composite material was evaluated by energy dispersive spectroscopy analysis (EDS) and further confirmed by Fourier Transform Infrared Spectroscopy (FTIR). EDS detects 0.26 wt % of Ag element. The changes in its functional properties, like; antibacterial, UV protection (UPF), and moisture management (MMT) on treatment were also worked out concerning untreated feeder fabric. Silver nano-mediated bioactive lyocell knit has executed 98% and 94% resistance against gram +ve and gram –ve bacterium respectively, improvement in the UPF value, and becoming moisture management fabric as revealed by the MMT standard. The biogenic fabric can potentially be utilized for hygienic apparel textiles.

Biosynthesis of silver nanoparticles using nitrate reductase from Aspergillus terreus N4 and their potential use as a non-alcoholic disinfectant.

Green technology has been developed for the quick production of stabilized silver nanoparticles (AgNPs), with the assistance of nitrate reductase from an isolated culture of Aspergillus terreus N4. The organism's intracellular and periplasmic fractions contained nitrate reductase, with the former demonstrating the highest activity of 0.20 IU/g of mycelium. When the fungus was cultivated in a medium comprising 1.056% glucose, 1.836% peptone, 0.3386% yeast extract, and 0.025% KNO3, the greatest nitrate reductase productivity of 0.3268 IU/g was achieved. Statistical modeling via response surface methodology was used to optimize the enzyme production. The periplasmic and intracellular enzyme fractions were found to convert Ag+ to Ag0, initiating synthesis within 20min, with predominant nanoparticle sizes between 25 and 30nm. By normalizing the effects of temperature, pH, AgNO3 concentration, and mycelium age with a variable shaking period for enzyme release, the production of AgNPs with the periplasmic fraction was optimized. The synthesis of nanoparticles occurred at temperatures of 30, 40, and 50°C, with the highest yield observed at 40 and 50°C during shorter incubation periods. Similarly, the nanoparticles were synthesized at pH levels of 7.0, 8.0, and 9.0, with the greatest production observed at pH 8.0 and 9.0 at lower incubation periods. The antimicrobial activity of AgNPs was demonstrated against common foodborne pathogens, including Staphylococcus aureus and Salmonella typhimurium, indicating their potential as non-alcoholic disinfectants.

Increased Stability of Silver Nanoparticles in Saline and Oxidizing Media in the Presence of Biogenic Amines

The research has been carried out to increase the stability of silver nanoparticles stabilized by maleic acid copolymers in saline and oxidizing media. It is shown that the stability of silver nanoparticles in NaCl and H2O2 solutions increases upon complexation with biocompatible amines, namely, histamine, Lys-OEt, and acetylcholine. The additional steric and electrochemical stabilization allows for maintaining significantly the stability of nanocomplexes in solutions of salts and oxidizing agents at 40 °C. The destruction of the nanocomplexes was studied by UV-vis spectroscopy, transmission electron microscopy, and gel permeation chromatography.

Ultrasonic-assisted green synthesis of silver nanoparticles through cinnamon extract: biochemical, structural, and antimicrobial properties

ABSTRACT Ultrasonic-assisted green synthesis of silver nanoparticles is gaining more attention owing to its benefits over conventional synthesis process. The main objective of this study was to synthesize silver nanoparticles with aqueous cinnamon extract using ultrasound-assisted extraction and their physico-chemical characterization. Total phenolic content, DPPH, FRAP of cinnamon aqueous extract were 315 mg GAE/g, 89% scavenging activity and 9.5 mmol Trolox eq/100 g reducing power respectively. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, X-rays Diffraction (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-rays (EDX), Fourier transform infrared (FTIR) and Nuclear Magnetic Resonance (NMR). XRD spectra depicted that the nanoparticles were crystallite in structure and 50 nm in size. SEM micrographs showed that nanoparticles were spherical in shape. EDX, FTIR and NMR spectra indicated that the phenolic compounds present in cinnamon aqueous extract played their role in capping and reducing the silver ions. Cinnamon-based silver nanoparticles showed potential antimicrobial activity against Gram negative and Gram-positive bacteria. Thus, cinnamon extract obtained through ultrasonic-assisted extraction could be a valuable source of polyphenols, which actively participated in the reduction and stabilization of silver nanoparticles.

Biologically Synthesized Silver Nanoparticles Efficiently Control Plant Pathogenic Bacteria-Erwinia carotovora and Ralstonia solanacearum

Biogenic nanoparticles are considered effective alternatives to chemical pesticides for the management of pathogenic plant diseases. This study was focused on the synthesis of stable silver nanoparticles (AgNPs) to control challenging plant pathogenic bacteria in vitro and in planta. We synthesized AgNPs by reacting different proportions of silver nitrate and aqueous extract of Hedera nepalensis. The physicochemical properties of the synthesized AgNPs were determined by using various physical techniques. The TEM analysis revealed the AgNPs less than 50 nm in size and spherical shaped. For antibacterial assays, different concentrations (1000–15.62 µg/mL, 2-fold dilutions) of the extract-free AgNPs (Ef-AgNPs) or extract-mixed AgNPs (Em-AgNPs), and fruit extracts (FE) were used against plant pathogenic bacteria Erwinia carotovora subsp. carotovora, Erwinia carotovora subsp. atroseptica, and Ralstonia solanacearum. In the in vitro assays, we found significant inhibition of both bacterial species in response to maximum concentrations of AgNPs. Overall, Ef-AgNPs exhibited a higher percent inhibition of bacterial pathogens. In potato tubers assay, complete inhibition of Erwinia carotovora was observed, except for the lowest AgNPs concentration of 15.62 µg/mL. Similarly, exposure of tomato plants to Ralstonia solanacearum suspensions (OD600 = 0.2) in the soil-drenching experiment and post-exposure treatment with 1000 µg/mL and 125 µg/mL of AgNPs resulted in disease inhibition. This study provides the basis that biogenic nanoparticles prepared from Hedera nepalensis are one of the best substitutes to synthetic pesticide, having displayed better results to control the growth of phytopathogenic microbes. However, field studies need to be conducted in a controlled environment to scale up the current work and find out the efficacy of nanoparticles on a larger scale.

Silver Nanoparticles Incorporated PVA‐MC Blends: A Systematic Approach To Understand Its Properties For Food Packaging Applications

AbstractHither‐to‐unknown one‐pot method for the synthesis and stabilization of silver nanoparticles (AgNPs) from silver nitrate (AgNO3) through uncross‐linked and cross‐linked polyvinyl alcohol/methyl cellulose (PVA/MC) blend using solution casting method is discussed in detail. The formed films were characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive X‐ray spectroscopy (SEM‐EDX), transmission electron microscopy (TEM) and analyzed for its physical, mechanical, biodegradable and antibacterial properties (particle size, water vapour transmission rate, water contact angle, thermogravimetric analysis (TGA), UV‐Vis spectroscopy and migration). SEM and TEM results indicated that the formation of silver nanoparticles are spherical in shape as well as nano in size. FTIR spectroscopic analysis indicates the existence of hydrogen bonds in cross‐linked blend and complex of silver (Ag) in uncross‐linked blend. Further, enhanced mechanical, water barrier, and thermal properties are observed for the films containing AgNPs. Antibacterial test by disc diffusion method showed that, uncross‐linked and cross‐linked blend with AgNPs have more inhibition (mm) against L. Monocytogenes (10.33), Klebsiella (9.67) (Gram‐positive) and Salmonella (9.33), E. Coli (8.33) (Gram‐negative) strains respectively. Migration studies demonstrated that the developed films could be suitable for fatty food packaging.

Determination of antioxidant activity by in situ synthesis of AgNPs using in-tube SPME coupled on-line to capillary liquid chromatography

A chromatographic system based on in-tube SPME coupled to capillary LC-DAD has been used to study the synthesis of silver nanoparticles using polyphenols in different scenarios: excess of the reducing agent or of the silver salt, addition of the cationic surfactants, and thermal synthesis. The optimized synthesis conditions allowed to quantify the polyphenols used as reducing agents, such as Trolox and chlorogenic acid. Two chromatographic peaks with different absorption spectrum were monitored during the syntheses. Depending on the molar relationship, a linear relation between the area of the chromatographic peaks and the concentration of the silver or polyphenol was established. For stabilization of silver nanoparticles, different cationic surfactants were used allowing to evaluate the role of anion (chloride and bromide) and of the alkyl chain. The proposed methodology can be used to determine chlorogenic acid up to 3 mM with a detection limit of 34 μM at λ= 400 nm. Chlorogenic acid was determined in dietary products with successful results. Precision (RSD=10%) and recovery (97–100%) were also satisfactory.Graphical

Toxicity assessment of poultry-waste biosynthesized nanosilver in Anabas testudineus (Bloch, 1792) for responsible and sustainable aquaculture development-A multi-biomarker approach

The current study investigates the potential utilization of poultry intestines for the synthesis of stable silver nanoparticles (AgNPs) and their impact on fish physiology. The AgNPs were synthesized and characterized using various analytical techniques. The toxicity of AgNPs on Anabas testudineus was evaluated, determining a 96-h LC50 value of 25.46 mg l−1. Subsequently, fish were exposed to concentrations corresponding to 1/10th, 1/25th, 1/50th, and 1/100th of the estimated LC50 for a duration of 60 days in a sub-acute study. A comprehensive range of biomarkers, including haematological, serum, oxidative stress, and metabolizing markers, were analyzed to assess the physiological responses of the fish. Additionally, histopathological examinations were conducted, and the accumulation of silver in biomarker organs was measured. The results indicate that silver tends to bioaccumulate in all biomarker organs in a dose- and time-dependent manner, except for the muscle tissue, where accumulation initially increased and subsequently decreased, demonstrating the fish's inherent ability for natural attenuation. Analysis of physiological data and integrated biomarker responses reveal that concentrations of 1/10th, 1/25th, and 1/50th of the LC50 can induce stress in the fish, while exposure to 1/100th of the LC50 shows minimal to no stress response. Overall, this study provides valuable insights into the toxicity and physiological responses of fish exposed to poultry waste biosynthesized AgNPs, offering potential applications in aquaculture while harnessing their unique features.

An innovative synthesis of (Ag0-pullulan-Ag+) as an optical nanoprobe for sensitive and selective detection of Fe2+ ion based on redox reaction

Herein, we Synthesized an efficacious optical nanoprobe (Ag0-pullulan-Ag+) for sensitive and discriminative detection of ferrous ions (Fe2+) over ferric ions (Fe3+) in solution. Pullulan (PUL) biopolymer was used as the reductant of excess AgNO3, at moderate heating, so that stable and dispersed silver nanoparticles (AgNPs or Ag0) were formed, which also contained an unreduced silver ion (Ag+), all intertwined in the pullulan polymeric matrix. Extensive characterization confirmed the role of PUL as a capping agent, while sharp Ag0 and Ag+ peaks were validated using X-ray photoelectron spectroscopy (XPS). The Ag0-PUL-Ag+ probe showed a sharp absorption maximum at 415 nm, having a majority size distribution around 20–30 nm, from TEM. The addition of Ag0-PUL-Ag+, acetate buffer pH 5.0, and Fe2+ under room temperature incubation led to Fe2+ reduction of available Ag+ to more AgNPs, based on redox reaction, with color progression from light yellow to yellow, orange, and brownish yellow. The ΔA@411 plotted against Fe2+ concentration was linear within 1.0–20.0 and 20.0–125.0 μM, with a limit of detection (LOD) of 0.15 μM. The assay was selective to only Fe2+ over other metal ions and was applied to Fe2+ detection in tap water and in ferrous fumarate tablets with satisfactory accuracy/precision. Our work showed that with careful control of nanomaterial synthesis conditions, a sensitive detection probe could be obtained for impressive analyte sensing/detection.