Herein, we describe the development of a novel colorimetric sensor based on silver nanoparticles decoratively anchored onto a graphene oxide scaffold (AgNPs@GO) for the sensitive and selective determination of cefazolin in complex biological and environmental matrices. The nanocomposite was synthesized through an in-situ citrate-mediated reduction strategy, affording spherical silver nanoparticles with a mean diameter of 18.6 +/- 4.2 nm uniformly dispersed across the graphene oxide surface. Comprehensive characterization employing FE-SEM, FT-IR, and XRD confirmed the successful immobilization of highly crystalline, phase-pure silver nanoparticles onto the exfoliated carbon support. The sensor operates on the principle of analyte-induced aggregation, transduced as a ratiometric change in the localized surface plasmon resonance absorption (A(650)/A(400)). Under optimized conditions (pH 7.0, 50 mM NaCl, 12 min incubation, 0.25 mg & centerdot;mL(-1) AgNPs@GO), the probe exhibited a linear response toward cefazolin across the concentration range of 0.5 to 75.0 & micro;M, with a limit of detection of 0.16 & micro;M. The sensor demonstrated excellent selectivity against structurally analogous antibiotics and common coexisting species, with notable tolerance to ionic strength up to 100 mM NaCl. Practical applicability was validated through quantitative recovery of cefazolin from spiked human serum (96.0-98.9%), river water (98.0-99.6%), and wastewater effluent (94.0-97.8%), with results statistically equivalent to those obtained by high-performance liquid chromatography. This AgNPs@GO platform reconciles operational simplicity with robust analytical performance, presenting a compelling alternative to conventional instrumentation for antibiotic monitoring in resource-limited settings.
present study reports eco-friendly green synthesis approach fabrication of manganese oxide (MnO), iron oxide (Fe2O3), and manganese ferrite spinel (MnFe2O4) nanoparticles utilizing aqueous extract of Citrus sinensis (orange) peel as a natural reducing and capping agent. The phytochemicals present in the orange peel extract, including flavonoids, phenolic compounds, and ascorbic acid, served as effective bio-reductants for metal ion reduction and stabilization of the resulting nanoparticles. The synthesized nanoparticles were comprehensively characterized using multiple analytical techniques including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometry (VSM). XRD analysis confirmed the successful formation of crystalline phases with average crystallite sizes of 14.05 nm for MnO, 24.17 nm for alpha-Fe2O3(hematite), and 30.66 nm for MnFe(2)O(4 )spinel structure, calculated using the Debye-Scherrer equation. FESEM micrographs revealed predominantly spherical morphology with mean particle sizes of 19.65 +/- 3.35 nm, 24.29 +/- 1.48 nm, and 31.31 +/- 3.92 nm for MnO, Fe2O3, and MnFe2O4, respectively, as determined by Gaussian distribution analysis. EDX spectroscopy confirmed the elemental composition and stoichiometric ratios of the synthesized nanoparticles without significant impurities. VSM measurements revealed superparamagnetic behavior for MnFe(2)O(4 )nanoparticles, making them suitable for biomedical applications. The antibacterial efficacy was systematically evaluated against Gramnegative Escherichia coli (ATCC 25922) and Gram-positive Staphylococcus aureus (ATCC 25923) using the agar well diffusion method at varying concentrations (62.5-500 & micro;g/mL). Results demonstrated concentration-dependent antibacterial activity for all nanoparticles. Notably, MnFe(2)O(4 )nanoparticles exhibited superior antibacterial performance with maximum inhibition zones of 30 mm and 25 mm against E. coli and S. aureus at 500 & micro;g/mL, respectively. The enhanced antibacterial activity of the mixed metal oxide nanoparticles is attributed to synergistic effects of manganese and iron ions in generating reactive oxygen species (ROS) and disrupting bacterial cell membrane integrity. These findings suggest that green-synthesized MnFe(2)O(4 )nanoparticles hold significant potential for antimicrobial applications in biomedical and environmental sectors.
It's a sustainable and environmentally friendly method for reducing agricultural waste, while in the meantime it helps for the production of additional valuables. The production of ZnO nanoparticles by using green method employing four different Zahidi date palm (Phoenix dactylifera L.) residue aqueous extracts such as kernels, spines, leaflets and fibers are reported in the present investigation. The phytochemical content analyses of the prepared extracts show a variation in secondary metabolites for each extract and are discussed to find its role in the formation of nanoparticles and morphology. Kernels extract exhibited the highest total phenolic and flavonoid contents, while leaflet extract showed the highest saponin contents, and spines extract contained the highest alkaloid content. The prepared biosynthesized ZnO nanoparticles were characterized using UV-visible, FTIR, XRD, FESEM, and EDX techniques.Distinct ZnO morphologies were obtained depending on the residues used during synthesis. Kernels extract produced flower-like nanostructures, spines extract generated spherical nanoparticles, leaflet extract formed sheet-like structure, and fiber extract resulted in dense irregular nanostructures. Since all synthesis conditions were maintained constant, the variation in ZnO morphology was mainly attributed to residue-dependent phytochemical differences.
Water pollution caused by synthetic dyes continues to attract serious attention from environmental researchers, particularly because many of these compounds are toxic, non-biodegradable, and remain in aquatic systems for long periods of time. This study developed a nanocomposite hydrogel utilising graphene oxide and a copolymer of acrylic acid and maleic anhydride, designated as GO/P(AA-MA), through free radical polymerisation. Its efficacy as an adsorbent for Fuchsin Basic (FB), a cationic dye commonly used in the textile industry and biological staining, was assessed. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM) were used to study the synthesised material. These tests showed that GO was successfully added to the polymer matrix and that the material had a rough, porous shape that was good for dye uptake. Batch experiments were conducted to investigate the influence of contact time, initial dye concentration, adsorbent mass, pH, ionic strength, and temperature on the adsorption behaviour. Kinetic data fitted the pseudo-second-order model very well (R2 > 0.99), while equilibrium data were best described by the Langmuir isotherm, giving a maximum monolayer capacity of about 285 mg g-1 at 298 K. Thermodynamic analysis indicated that the process is spontaneous, endothermic, and entropy-driven. The adsorbent was further tested over five adsorption-desorption cycles with only a modest loss of efficiency, which suggests that GO/P(AA-MA) is a promising and reusable material for the treatment of dye-contaminated water.
Polymer-based nanoparticles are colloidal systems composed of either natural or synthetic polymers. Bromocriptine, a semi-synthetic ergot alkaloid, binds to D2 dopamine receptors, decreasing prolactin secretion. It is prescribed for conditions like neuroleptic malignant syndrome, acromegaly, infertility, and hyperprolactinemia. Bromocriptine mesylate has limited water solubility, with gastrointestinal absorption between 28% and 37%. Nevertheless, its oral bioavailability is reduced to about 6% due to first-pass metabolism in the liver. This study aimed to develop and assess a polymeric nanoparticle system containing bromocriptine mesylate to improve its solubility, wettability, dissolution rate, and stability. This would facilitate more efficient delivery of bromocriptine mesylate through a fast-dissolving oral film. The method involved polymeric nanoparticle emulsification and solvent evaporation. Initially, the polymer solution was emulsified in an aqueous nanomaterial phase, then solvent evaporation was performed. PEG400 and poloxamer 188 served as the internal polymers, while Tween 80 functioned as the surfactant to produce the polymeric nanoparticles. The nanoparticle formulated with PEG400 as the internal polymer had a size range of 154 nm to 537 nm. The entrapment efficiency (EE) was tested on the selected formula (F4), which had the smallest particle size, resulting in 92%. Drug release reached 96% within 60 minutes. FTIR analysis showed no changes in the fingerprint region of bromocriptine
A new family of nanocrystalline copper(II) bis(keto-imino) complexes bearing the chlorinated Schiff-base ligand (Z)-ethyl 4-chloro-3-(phenylimino)butanoate (EClN) was synthesized and structurally characterized at the nanoscale. The parent complex CuEClN was prepared by condensation of EClN with copper(II) acetate, then five-coordinate adducts CuEClN-py, CuEClN-bpy, CuEClN-C1V+.PF6- and CuEClN-V-2(2+).2PF(6)(-) were obtained through axial coordination of pyridine, 4,4(y)-bipyridine, mono-methyl viologen hexafluorophosphate (C1V+.PF6-) and propylene-bridged bis-viologen bis(hexafluorophosphate) (V-2(2+).2PF(6)(-) ). The compounds were identified by FT-IR, LC-MS, UV-Visible and TGA analyses. Powder X-ray diffraction confirmed the crystalline character of every compound, and crystallite sizes were quantified in the nanoscale (range approximate to 6 - 81 nm) by both Scherrer and Williamson-Hall (W-H) models. The W-H analysis simultaneously delivered the lattice-strain (epsilon) and revealed that bulky charged axial viologens generate the strongest distortion (epsilon = 1.56 & times; 10(-)& sup3; for CuEClN-V-2(2+).2PF(6)(-) ), whereas the small, flexible parent ligand EClN gives the most ordered lattice. FE-SEM micrographs corroborated the XRD trend: chlorinated viologen complexes display sub-10 & micro;m aggregates with finer secondary particles. UV-Visible spectra in DMF/DMSO show the d-d transitions expected for square-planar (CuEClN) and square-pyramidal (adducts) geometries. Chemical reduction of the viologen-bearing complexes by activated zinc and electrochemical reduction by cyclic voltammetry in DMF (under Ar) furnished, respectively, intermolecular pi-dimers (CuEClNC1V center dot)(2) and an intramolecular bis-viologen pi-dimer within CuEClNV2, monitored by characteristic absorption bands at approximate to 380 nm and approximate to 554-560 nm. The reversibility upon air re-oxidation establishes these nanocrystalline complexes as redox-triggered molecular switches and promising candidates for nano-electronic and smart-material applications.
A novel Schiff base ligand (2E,3E)-3-((6-(((1E,2E)-1,2-diphenyl-2-(thiazol-2-ylimino) ethylidene) amino)pyridin-2-yl)imino)butan-2-one oxime derived from thiazol-2-amine was synthesized through a three-step procedure involving sequential condensation reactions of 2,6-diaminopyridine with diacetyl monoxime (compound A), followed by reaction with benzil (compound B), and finally with thiazol-2-amine to yield the target ligand (SBTOx-OH). A nano complex of the above ligand was prepared by reacting it with gold(III) chloride dissolved in ethanol. The ligand (SBTOx-OH) and its gold(III) complex were characterized using spectroscopic techniques including FTIR, 1H-NMR, 13C-NMR, UV-Vis spectroscopy, atomic absorption, in addition to melting point determination, molar conductivity, elemental microanalysis (C.H.N), and magnetic susceptibility measurements. The complex was prepared in a 1:1 (M:L) ratio. The combined results of these measurements support that the geometry of the gold(III) complex is square planar. The cytotoxic activity of the ligand and its gold complex was evaluated against breast cancer cells (MCF-7), with a selectivity index (SI) of approximately 1.16 relative to normal human dermal fibroblast cells (HdFn). Although the gold complex exhibited a marginally lower IC50 against MCF-7 (111.2 mu g/ mL) compared to the free ligand (122.86 mu g/mL), the free ligand displayed a more favorable selectivity index (SI = 3.35 vs. 1.16). The modest SI of the gold complex indicates limited preferential toxicity toward cancer cells, and further structural optimization is required to improve the therapeutic window. It should be noted that no positive control drug was included in the cytotoxicity assay, which represents a limitation of the current study. Molecular docking against the EGFR tyrosine kinase (PDB: 3DKF) indicated moderate binding affinities for the synthesized compounds, though the correlation between docking scores and experimental cytotoxicity was not straightforward.
The manufacture of nanoparticles using plant extracts is an important and useful biological process compared to other manufacturing methods. The reason for this is that the biological or green nanotechnology method where there is no problem in maintaining and preserving plant cell cultures, so there is no fear of mutation in the preparation medium, as is the case with bacterial or fungal cultures. It is also easy to prepare and manufacture, usually in a few quick steps, and is inexpensive. The aim of this research was to find a safer, more environmentally friendly, inexpensive, and harmless method of synthesizing silver nanoparticles from Rosmarinusofficinalis extract and using them as a fungicide. The nanoparticles (silver nanoparticles) were Biosynthesized by using the aqueous extract of the rosemary plant and using it as a biological agent to reduce silver nitrate to nano-sized silver ions, by distilling the plant extract on the silver nitrate solution and observing the color change process, which indicates the formation of silver nanoparticles. Scientific tests confirming the green manufacturing process were conducted. Silver nanoparticles were then used as a fungicide in the laboratory for fungi that produce certain mycotoxins. Silver nanoparticles can be synthesized from R. officinalis leaf extract. The silver nanoparticles appeared to have a semi-pyramidal shape with a size of 63.65 nm when examined by Scanning Electron Microscopy, UV/Vis spectroscopy showed a peak at a wavelength of 345 nm, while X-ray diffraction showed four distinct diffraction peaks that matched the standard with which it was compared. The Atomic Force Microscopy examination showed that the size of the surface topography was 29.65 nanometers. Test results showed the effectiveness of three concentrations of silver (Ag) nanoparticles on certain pathogenic fungi that produce mycotoxins. The results of the experiment demonstrated the effectiveness of these nanoparticles. was very high in inhibiting the studied fungal species on PDA medium. It was observed that the percentage of inhibition increased with increasing concentrations, as the inhibition results at the concentration (ppm /L 100) of silver nanoparticles showed 100% complete inhibition with the two species Aspergillusnigerand Fusariumsolani, while 73.3% inhibition was observed for the same concentration with F. verticillioides. The study confirmed that the biosynthesis of nanoparticles through the use of plant extracts is a safe, fast, inexpensive and effective method. The study showed that nanoparticles prepared from rosemary extracts can be used as an antifungal agent against mycotoxins in the laboratory, with an inhibition rate of 100%.
This study investigated the green synthesis of zinc oxide nanoparticles using the aqueous leaf extract of Dombeya wallichii as a plant-based source of reducing and stabilizing agents. The synthesized ZnO-NPs were examined by Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Spectroscopy, and Atomic Force Microscopy in order to confirm their formation and evaluate their main physicochemical characteristics. The biological activity of the aqueous leaf extract and the green-synthesized ZnO-NPs was assessed through antioxidant and cytotoxicity assays. The antioxidant potential was measured using the DPPH free radical scavenging assay, whereas cytotoxic activity was evaluated by the MTT assay against human breast cancer cells (MCF-7) and normal mammary epithelial cells (MCF-10). The obtained results showed that both treatments produced concentration-dependent effects. However, ZnO-NPs showed higher free radical scavenging activity and stronger inhibitory effects against MCF-7 cells than the crude plant extract. Their effect on MCF10 cells was comparatively lower, which may indicate a selective action toward cancer cells. Based on these findings, the aqueous leaf extract of D. wallichii appears to be a suitable natural medium for the green synthesis of ZnO-NPs. The resulting nanoparticles showed promising antioxidant and anticancer properties, suggesting their potential value as bioactive nanomaterials for further breast cancer-related investigations.
This study investigates the effect of incorporating silver oxide (AgO) nanoparticles into a polymer composite made of polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) were mixed in a 1:1 ratio. Nanocomposite films were prepared using casting method process with adding different concentrations of AgO nanoparticles (0.3, 0.5 and 0.7 wt%). Structural properties, Fourier-transform infrared (FTIR) and scanning electron microscope (SEM) analyzes were used to evaluate the effect of AgO incorporation on the properties of the polymer blend. Samples' optical properties were tested by measuring their UV-Visible spectra. The findings show that the addition of AgO nanoparticles significantly improves the structural and optical properties of the mixture. For the nanocomposites containing 0.3, 0.5, and 0.7 wt% AgO, the optical band gap gradually decreased from 5.35 eV (pure mixture) to 5.25, 5.20, and 5.16 eV, respectively.
In this work, a 1:1 molar ratio of TiO2 and barium salts was used to prepare a BaTiO3 nanocomposite. A precursor solution was prepared through the chemical precipitation method and then hydrothermally treated to achieve different morphologies and structural forms of the nanocomposite. X-ray diffraction, which was used for structural characterization, demonstrated that the nanocomposite had an average particle size of approximately 56 nm and validated its crystalline nature. Surface morphology and particle size were assessed through scanning electron microscopy. The elemental composition and weight percentages of constituent elements were also determined by employing energy-dispersive X-ray spectroscopy to confirm the effective synthesis of the nanocomposite. These results were then compared with the anticipated theoretical values.
The rapid expansion of green nanotechnology has driven renewed interest in environmentally safe approaches for producing biomedical nanomaterials. Among these, zinc oxide nanoparticles (ZnONPs) have attracted considerable attention due to their biocompatibility, chemical stability, and notable anticancer properties. Their nanoscale dimensions enhance cellular interactions and promote selective toxicity toward malignant cells, making them promising candidates for therapeutic development. In this study, ZnONPs were synthesized using an aqueous extract of Urtica pilulifera leaves as a natural reducing and stabilizing agent. Phytochemical screening confirmed the presence of flavonoids, phenolics, tannins, alkaloids, and terpenoids, all of which contributed to nanoparticle formation. The synthesized particles were characterized using FE-SEM to verify their optical, structural, and morphological features, UV-Vis spectroscopy, XRD, FTIR, and. Cytotoxic effects were evaluated against U87 glioblastoma cells using the MTT assay. Characterization revealed that the ZnONPs were spherical, crystalline, and coated with phytochemicals from the plant extract. Biological assays demonstrated a concentration-dependent reduction in U87 cell viability, accompanied by clear apoptotic indicators such as cell shrinkage and membrane disruption. The findings highlight the strong anticancer potential of green-synthesized ZnONPs, emphasizing their suitability as eco-friendly and effective agents for future applications in nanomedicine.
The application of nanotechnology in cancer therapy has attracted significant attention in recent years. Among various nanomaterials, silver nanoparticles (AgNPs) have demonstrated promising potential due to their relatively low toxicity toward normal cells, cost-effectiveness, and potential ability to selectively target cancer cells. This study aimed to evaluate the inhibitory biological activity of silver nanoparticles against two human breast cancer cell lines, MCF-7 and MDA-MB-231. Silver nanoparticles were characterized using several analytical techniques including X-ray Diffraction (XRD), Ultraviolet-Visible Spectroscopy (UV-VIS), Energy Dispersion X-ray (EDX), Atomic Force Microscopy (AFM), and Filed Emission Scanning Electron Microscopy (FE-SEM). The characterization results confirmed the successful synthesis of quasi-spherical silver nanoparticles with particle sizes ranging from 30 to 40 nm. The cytotoxic effect of the synthesized AgNPs was investigated using the MTT assay on both MCF-7 and MDA-MB-231 cell lines at six different concentrations. The results indicated a concentration-dependent inhibitory effect of silver nanoparticles on both cancer cell lines, with a stronger cytotoxic activity observed against the MDA-MB-231 cell line. These findings highlight the potential of silver nanoparticles as promising anticancer agents against breast cancer cells and support the need for further investigations using more advanced biological models.
Hydrogels were synthesized via free-radical polymerization using sodiumg-poly(acrylamide-crotonic acid) alginate, with reactant concentrations optimized using the Taguchi method. Furthermore, a nano-hydrogel was prepared by adding silica nanoparticles. The hydrogel and nanocomposite were characterized using FTIR, FESEM-EDX, TEM, XRD, TGA, and BETBJH spectroscopy. The study focused on the removal of lead (Pb2+) ions from aqueous solutions. The maximum adsorption capacity was 243.667 mg/g at 35 degrees C, and the adsorption kinetics were found to be consistent with a pseudo-second-order reaction model. Moreover, the adsorption of lead (Pb2+) ions followed Freundlich and Temkin isothermic patterns. The Pb2+ removal study at different temperatures (5, 15, 25, and 35 degrees C) demonstrated that the adsorption process is primarily a physical one. Gibbs free energy, enthalpy, entropy, and equilibrium constant were calculated. In this study, we investigated the effects of both temperature and pH. The results showed that with increasing pH and temperature, adsorption efficiency increased, consistent with the endothermic nature of the process, which was spontaneous. The Pb2+ removal efficiency was verified after washing the adsorbent with sodium hydroxide, and the results were very encouraging, even after five washes.
The precise monitoring of dopamine, a vital neurotransmitter involved in the regulation of mood, cognition, and motor control, is of great importance. In this context, carbon paste electrodes have attracted considerable attention due to their ease of preparation, cost-effectiveness, and ability to be modified for enhanced sensitivity and accuracy. In the present study, NH2-MIL-88B(Fe) was synthesized and characterized using fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) analyses, and subsequently employed to modify a carbon paste electrochemical sensor for the detection of dopamine in human and pharmaceutical samples and in the presence of phenylalanine. The synergistic effect of the synthesized metal- organic framework (MOF) combined with graphite led to a remarkable improvement in sensor performance, providing a wide linear response range from 0.7-100 mu M and 100-900 mu M, with an exceptionally low detection limit of 0.18 mu M for dopamine, indicative of the high performance of the optimized electrode. Kinetic analysis further revealed a transfer coefficient (alpha) of 0.8 and a diffusion coefficient (D) of 4.3 & times; 10(-6) cm(2)/s.
The emergence of nanotechnology has enabled novel strategies for treating parasitic infections, particularly through the use of biosynthesized nanoparticles. This study focuses on the green synthesis of silver nanoparticles (AgNPs) using white mushroom (Agaricus bisporus) extract as a bioreducing and stabilizing agent and evaluates their therapeutic efficacy against Leishmania donovani in a murine model of visceral leishmaniasis (VL). The synthesized AgNPs were characterized using X-ray diffraction (XRD), UV-visible spectroscopy, and scanning electron microscopy (SEM), confirming their spherical morphology, crystalline structure, and surface plasmon resonance at similar to 430 nm. Mice were divided into five treated, and AgNPs + Pentostam-treated. Treatment with AgNPs, either alone or in combination with Pentostam, significantly reduced liver and spleen enlargement or restored hematological parameters toward normal levels. The combined treatment showed the most notable therapeutic benefit, indicating a synergistic effect. These findings support the potential of mushroom-mediated AgNPs as a biocompatible and effective adjunct therapy for visceral leishmaniasis, offering a sustainable and less toxic alternative to conventional treatments.
Corrosion is a significant chemical and electrochemical process that leads to the degradation of metals through reactions with their environment including air, moisture, acids, and salts. This occurrence represents serious industrial and economic issue, causing significant financial losses annually and affecting the soundness of metal structures such as bridges, pipelines, and industrial equipment. In light of the critical need to mitigate corrosion damage, scientific research has prioritized the study of its underlying mechanisms and prevention strategies. Key advancements include the application of corrosion inhibitors, protective coatings, and nanomaterials, all of which have demonstrated significant efficacy in lowering corrosion rates and enhancing the longevity of metallic substrates. In this study, novel nanocomposites were synthesized, beginning with the preparation of 2,5-dimercapto-1,3,4-thiadiazole [1]. This precursor was obtained through the reaction of NH2NH2.H2O (0.01 mol, 99%) with carbon disulfide (0.02 mol). Subsequently, compound [1] was reacted with chloroacetic acid and anhydrous sodium carbonate in distilled water to yield 2,2'-((1,3,4-thiadiazole-2,5-diyl)bis(sulfanediyl))diacetic acid [2]. To prepare the corresponding acid chloride, compound [2] was treated with thionyl chloride in benzene to produce compound [3]. Finally, the O-chitosan derivative [4] was synthesized via the esterification of chitosan with compound [3] in an acidic aqueous medium, following the Fischer esterification method. O,N-carboxymethyl chitosan [5] was synthesized via the reaction of chitosan with compound [4] in a mixture of chloroform and pyridine. Subsequently, the modified chitosan derivatives [4, 5] were blended with carboxymethyl cellulose (CMC) to yield polymer blends [6, 7]. These blends were further incorporated with copper, silver, or zinc nanoparticles using a hotplate stirrer for three hours to produce nanocomposites [8-13]. The structural and morphological characteristics of the synthesized polymers and composites were characterized using (FTIR), (1H-NMR), Field Emission Scanning Electron Microscopy (FESEM), and Transmission Electron Microscopy (TEM). Testing the corrosion inhibition of modified CS, modified CS /CMC and nanocomposites on mild steel in 0.1M HCl was conducted by weight loss analysis and electrochemical measurements were used to explore the corrosion inhibition study. The results show that nanocomposites [11-13] have a higher inhibition rate than blended polymer [7], modified CS[5] against the corrosion of carbon steel.
This work was conducted to develop and test biosynthesized electrochemical nanosensors from the plants Ficus elastica and Acalypha indica for the detection of lead (Pb2+), cadmium (Cd2+), and mercury (Hg2+) ions in industrial wastewater, river water, and groundwater. Metal oxides and metal nanoparticles (CuO, Ag, and ZnO) were obtained from these sensors. Carbon paste (CPE) electrodes were modified using biosynthesized nanomaterials and polyaniline (PANI) to form the electrochemical sensors. The sensor voltage was measured using cyclic voltage (CV) and square wave voltage (SWV). The developed sensors exhibited detection limits ranging from 0.07 to 0.16 & micro;g/L. Sensor recovery rates on real, supported industrial water samples ranged from 97% to 104%, confirming the sensors' effectiveness and high analytical sensitivity. Green synthesis offers a cost-effective, environmentally friendly, and sustainable pathway for producing high-performance electrochemical sensors used in the field monitoring of heavy metals in industrial environments.
The present work investigates the adsorption kinetics and pH-responsive behaviour of malachite green (MG) dye onto a novel pectin/poly(Nisopropylacrylamide-co-acrylic acid) nano-hydrogel synthesized via free-radical copolymerization. The nano-hydrogel was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and BET surface area measurements. Batch adsorption experiments were conducted to evaluate the effects of adsorbent dosage (0.006-0.06 g), contact time (1-150 min), and solution pH (2-10) on MG removal efficiency. The optimum adsorbent weight was found to be 0.008 g, yielding an adsorption capacity of 596.04 mg/g with 95.37% removal efficiency. Kinetic analysis revealed that the pseudo-second-order model provided the best fit (R2 approximate to 1.000; RMSE = 0.89 mg/g) with a calculated equilibrium capacity of 605.13 mg/g, suggesting chemisorption as the rate-controlling mechanism. The Weber-Morris intraparticle diffusion model indicated a two-stage process involving rapid surface adsorption followed by gradual pore diffusion. The point of zero charge (pH(PZC)) was determined at pH 4.2, explaining the enhanced adsorption capacity observed at higher pH values where the surface acquires a net negative charge. MG adsorption increased from 515.21 mg/g at pH 2 to 608.96 mg/g at pH 10, confirming electrostatic attraction as a dominant mechanism. Regeneration studies demonstrated that the nano-hydrogel retained 87.8% of its initial adsorption capacity after five adsorption-desorption cycles using 0.1 M HCl/50% ethanol eluent. Furthermore, the adsorbent maintained >79% removal efficiency in simulated industrial wastewater containing competing ions and organic co-contaminants.
Herein, the synthesis of a novel eco-friendly hydrogel composite was carried out using sodium carboxymethyl cellulose (SCMC) and methacrylic acid (MAA) as major monomers to produce free radical polymerization combined with modified bentonite. Both PMAA added functional groups and increased the density of functional groups on the surface for more efficient reaction kinetics with AAP, while sodium-modified bentonite also significantly improved BET surface area, cation-exchange capacity (CEC), and structural integrity-all contributing to a clearly defined porous structure containing abundant active sites. FTIR, XRD, BET, FE-SEM and TGA were used to characterize the composite and confirm its structural, chemical and morphological properties. The influence of varying adsorbent dosage, contact time, solution pH and temperature were evaluated through batch adsorption tests for its removal on the crystal violet (CV) dye. Through optimization of parameters such as pH (pH = 8) and equilibrium time (t = 72 h), a maximum adsorption capacity of the hydrogel was reached, equal to 140.56 mg & centerdot;g-1, whereas the optimal removal efficiencies towards toxic metals were computed at T = 5 degrees C. Results obtained from adsorption data fitted the Langmuir isotherm and suggested monolayer chemisorption on a homogenous surface. Thermodynamic calculation indicated Delta S degrees = -9.108 J & centerdot;mol-1 & centerdot;K-1, Delta G degrees = +2.523 kJ & centerdot;mol(-1) and Delta H degrees = -10.485 kJ & centerdot;mol(-1) that presented the moderate spontaneity and exothermic reaction stage during the crystallization process. The PMAA/ SCMC/modified bentonite hydrogel shows a good structural property and an exceptional adsorption stability for CV dye, as proved by above mentioned findings. In summary, this composite exhibited a potential clean adsorbent for high performance wastewater treatment.
