Comparative study between Phragmites australis root and rhizome extracts for mediating gold nanoparticles synthesis and their medical and environmental applications

A comprehensive assessment of water quality in Fayoum depression, Egypt: identifying contaminants, antibiotic pollution, and adsorption treatability study for remediation

This study aimed to assess the current water quality status across various regions within the Fayoum depression by examining water canals, drains, and potential contaminants impacting public health and the local ecosystem. Additionally, an adsorption treatability investigation was conducted on various antibiotics identified during the assessment. Fifteen sampling points were selected across the Fayoum depression, covering surface water bodies and agricultural drainage systems during both winter and summer seasons. Physico-chemical, microbiological, and antibiotic analyses were performed on collected water samples. The water quality parameters investigated included pH, electrical conductivity, total dissolved solids (TDS), total coliforms, fecal coliforms, and concentrations of antibiotics such as ciprofloxacin and tetracycline. The findings revealed significant variations in water quality parameters among different water sources, categorizing them into three types: irrigation canals, polluted canals, and drains. High contamination levels were observed in certain water canals and drains due to untreated sewage and agricultural drainage discharge. Notably, elevated TDS levels (exceeding 1200 mg/L), microbial indicators count (with total coliforms reaching up to 2.3 × 106 CFU/100 mL), and antibiotics (with concentrations of ciprofloxacin and tetracycline exceeding 4.6 µg/L) were detected. To mitigate antibiotic contamination, a Phyto-adsorption treatability study using magnetite nanoparticles prepared with Phragmites australis plant extract demonstrated promising results, achieving complete removal of high antibiotic concentrations with an adsorption capacity of up to 67 mg/g. This study provides updated insights into water quality in the Fayoum depression and proposes a novel approach for addressing antibiotic contamination, potentially safeguarding human and environmental health.

Facile one-step synthesis of gold nanoparticles using Viscum album and evaluation of their antibacterial potential

Nanostructure gold nanoparticles (Au NPs) are well-known biological active materials, synthesised under different environment-friendly approaches that has gained significant interest in the field of biomedicine. This study investigated a novel, fast, easy, cost-effective and the eco-friendly method to synthesise Au NPs from mediated Viscum album Linn plant extract, where the plant metabolites act as stabilising and reducing agents. The synthesised Au NPs were analysed by UV/Vis spectroscopy that gave strong signals and a sharp absorption peak at 545nm due to the presence of surface plasmon resonance (SPR) bands. In addition, energy dispersive X-ray spectroscopy (EDX) showed that strong signals of Au NPs appeared at 9.7 and 2.3keV, as the rays of light passed. X-ray diffraction recognised the crystalline material and provided information on the cell unit that the synthesised Au NPs are face-centreed cubic in structure. The diffraction of X-ray spectra showed intense peaks at 38.44°, 44.7°, 44.9° and 77.8°. The mediated V. album plant extracts and synthesised Au NPs were screened against gram-positive and gram-negative (Enterobacter , Salmonella typhi , Escheria coli and Bacillus subtilis ) bacterial strains, confirming their antibacterial potential. Au NPs showed strong antibacterial activity due to its unique steric configuration. Au NPs damaged bacterial cell membrane leading to the leakage of the cytoplasm and death of the cell.

Recent Advances and Perspectives of Nanomaterials in Agricultural Management and Associated Environmental Risk: A Review

The advancement in nanotechnology has enabled a significant expansion in agricultural production. Agri-nanotechnology is an emerging discipline where nanotechnological methods provide diverse nanomaterials (NMs) such as nanopesticides, nanoherbicides, nanofertilizers and different nanoforms of agrochemicals for agricultural management. Applications of nanofabricated products can potentially improve the shelf life, stability, bioavailability, safety and environmental sustainability of active ingredients for sustained release. Nanoscale modification of bulk or surface properties bears tremendous potential for effective enhancement of agricultural productivity. As NMs improve the tolerance mechanisms of the plants under stressful conditions, they are considered as effective and promising tools to overcome the constraints in sustainable agricultural production. For their exceptional qualities and usages, nano-enabled products are developed and enforced, along with agriculture, in diverse sectors. The rampant usage of NMs increases their release into the environment. Once incorporated into the environment, NMs may threaten the stability and function of biological systems. Nanotechnology is a newly emerging technology, so the evaluation of the associated environmental risk is pivotal. This review emphasizes the current approach to NMs synthesis, their application in agriculture, interaction with plant-soil microbes and environmental challenges to address future applications in maintaining a sustainable environment.

Brown Seaweed (Padina australis) Extract can Promote Performance, Innate Immune Responses, Digestive Enzyme Activities, Intestinal Gene Expression and Resistance against Aeromonas hydrophila in Common Carp (Cyprinus carpio)

Eight-week oral administration of Padina australis ethyl acetate extract at 100, 200, and 400 mg/kg diets was assessed on the growth performance, tight junction proteins, intestinal immunity, and disease resistance to Aeromonas hydrophila in common carp (Cyprinus carpio). A total of 300 healthy common carp weighing around 14.8 ± 0.03 g were randomly assigned into four equal groups within 12 glass aquariums, each in three replicates (25 fish/tank), for the feeding trial experiment. The first group served as the control group and was fed an un-supplemented diet, whilst the other three groups were offered diets containing graded amounts of Padina australis ethyl acetate extract at 100, 200, and 400 mg/kg, respectively. The growth indices, including final weight, length, weight gain rate, specific growth rate, and feed conversion ratio, were meaningfully improved in fish fed with the algae at 200 and 400 mg/kg compared to the control fish (p < 0.05). Similarly, digestive enzyme activities and serum immune parameters were significantly higher in all treatments, especially 200 and 400 mg/kg fed groups, compared to the control (p < 0.05). In parallel, significant upregulation of genes related to integrity and the immune system was shown in the intestine of these treatment groups compared to control fish (p < 0.05). When fish were challenged with A. hydrophila, the cumulative survival percentages were 53.3% (p = 0.215), 70.0 % (p = 0.009), and 76.7% (p = 0.002) in fish fed 100, 200, and 400 mg/kg diets, respectively, compared to 36.7% survival in control fish (p = 0.134). These data show that the eight-week dietary administration of P. australis extract to common carp can enhance growth performance, digestive enzyme activity, immune response, and disease resistance to A. hydrophila infection.

Biogenic synthesis of reduced graphene oxide from Ziziphus spina-christi (Christ's thorn jujube) extracts for catalytic, antimicrobial, and antioxidant potentialities

In the current work, various concentrations of the aqueous extract of Ziziphus spina-christi were employed for the phytoreduction of graphene oxide (GO). The green synthesized reduced graphene oxide (rGO) was characterized through UV-Vis spectrometry, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDX). Gas chromatography-mass spectrometry (GC-MS) denoted the presence of numerous phytoconstituents including ketones, terpenoids, fatty acids, esters, and flavonoids, which acted as reducing and capping agents. The obtained results indicated the increase in rGO yield and shape with increasing the extract concentration. The optimized rGO was instantaneously ~100% removed methylene blue (MB) from the water at 5 mg L-1. However, the removal efficiency was slightly declined to reach 73.55 and 65.1% at 10 and 15 mg L-1, respectively. A powerful antibacterial activity for rGO particularly against gram-negative bacteria with a high concentration of 2 × 108 CFU mL-1 was confirmed. Furthermore, rGO demonstrated promising and comparable antioxidant efficiency with vitamin C against DPPH free radical scavenging. While vitamin C recorded 13.45 and 48.4%, the optimized rGO attained 13.30 and 45.20% at 12 and 50 μg mL-1, respectively.

Highly sensitive and selective colorimetric detection of Pb(ii) ions using Michelia tonkinensis seed extract capped gold nanoparticles

In this study, gold nanoparticles (AuNPs) were synthesized via a green and environmentally-friendly approach and applied as a colorimetric probe for detecting Pb2+ ions in aqueous solution. Instead of toxic chemicals, Michelia tonkinensis (MT) seed extract was used for reducing Au3+ and stabilizing the formed AuNPs. The synthesis conditions, including temperature, reaction time, and Au3+ ion concentration, were optimized at 90 °C, 40 min, and 1.25 mM, respectively. The physicochemical properties of the produced MT-AuNPs were assessed by means of transmission electron microscopy, X-ray diffraction, field emission scanning electron microscopy, dynamic light scattering, and Fourier-transform infrared spectroscopy. The characterization results revealed that the MT-AuNPs exhibited a spherical shape with a size of about 15 nm capped by an organic layer. The colorimetric assay based on MT-AuNPs showed excellent sensitivity and selectivity toward Pb2+ ions with the limit of detection value of 0.03 μM and the limit of quantification of 0.09 μM in the linear range of 50-500 μM. The recoveries of inter-day and intra-day tests were 97.84-102.08% and 98.78-102.34%, respectively. The MT-AuNPs probe also demonstrated good and reproducible recoveries (98.71-101.01%) in analyzing Pb2+ in drinking water samples, indicating satisfactory practicability and operability of the proposed method.

Phytofabrication of bimetallic silver-copper/biochar nanocomposite for environmental and medical applications

In the current study, a novel, green, low-cost, and sustainable path for the phyto-fabrication of Ag-Cu biochar nanocomposite (Ag-Cu/biochar) by Atriplex halimus biomass and aqueous extract is described. Surface plasmon resonance peaks were detected at 450 nm and 580 nm signifying the formation of both silver and copper nanoparticles, respectively on the biochar surface. XRD analysis confirmed the crystal structure of the phytosynthesized Ag-Cu/biochar whereas FT-IR, SEM, EDX, and XPS analyses confirmed the successful phytofabrication of the composite. Ag and Cu nanoparticles loaded on the biochar surface were almost spherically-shaped with a particle size ranging from 25 nm to 45 nm. Zeta potential of -25.5 mV showed the stability of Ag-Cu/biochar. The potential of this novel nanocomposite in the removal of doxycycline (DOX) was evident under different conditions as it reached nearly 100% under the optimum reaction conditions (DOX concentration; 50 ppm, pH; 9, a dose of Ag-Cu/biochar; 0.01 g, temperature; 25 °C, and H₂O₂ concentration; 100 mM). The promising regeneration of Ag-Cu/biochar was evident as the removal efficiency was 81% after 6 consecutive cycles. Ag-Cu/biochar was also shown an excellent antimicrobial activity against gram-negative bacteria as well a promising antioxidant activity.

Recent advances on botanical biosynthesis of nanoparticles for catalytic, water treatment and agricultural applications: A review

Green synthesis of nanoparticles using plant extracts minimizes the usage of toxic chemicals or energy. Here, we concentrate on the green synthesis of nanoparticles using natural compounds from plant extracts and their applications in catalysis, water treatment and agriculture. Polyphenols, flavonoid, rutin, quercetin, myricetin, kaempferol, coumarin, and gallic acid in the plant extracts engage in the reduction and stabilization of green nanoparticles. Ten types of nanoparticles involving Ag, Au, Cu, Pt, CuO, ZnO, MgO, TiO₂, Fe₃O₄, and ZrO₂ with emphasis on their formation mechanism are illuminated. We find that green nanoparticles serve as excellent, and recyclable catalysts for reduction of nitrophenols and synthesis of organic compounds with high yields of 83-100% and at least 5 recycles. Many emerging pollutants such as synthetic dyes, antibiotics, heavy metal and oils are effectively mitigated (90-100%) using green nanoparticles. In agriculture, green nanoparticles efficiently immobilize toxic compounds in soil. They are also sufficient nanopesticides to kill harmful larvae, and nanoinsecticides against dangerous vectors of pathogens. As potential nanofertilizers and nanoagrochemicals, green nanoparticles will open a revolution in green agriculture for sustainable development.

Green synthesis of bimetallic Ag/ZnO@Biohar nanocomposite for photocatalytic degradation of tetracycline, antibacterial and antioxidant activities

In this work, a simple and green synthesis procedure for phytofabrication Zinc oxide-silver supported biochar nanocomposite (Ag/ZnO@BC) via Persicaria salicifolia biomass is investigated for the first time to uphold numerous green chemistry such as less hazardous chemical syntheses. XRD technique showed the crystal structure of the phytosynthesized Ag/ZnO@BC, whereas UV-visible spectroscopy, FT-IR, SEM, EDX, TEM, and XPS analyses indicated the successful biosynthesis of the nanocomposite. Testing the photocatalytic potential of this novel nanocomposite in the removal of TC under different conditions unraveled its powerful photodegradation efficiency that reached 70.3% under the optimum reaction conditions: TC concentration; 50 ppm, pH; 6, a dose of Ag/ZnO@BC; 0.01 g, temperature; 25 °C, and H₂O₂ concentration; 100 mM. The reusability of Ag/ZnO@BC was evident as it reached 53% after six cycles of regeneration. Ag/ZnO@BC was also shown to be a potent antimicrobial agent against Klebsiella pneumonia as well as a promising antioxidant material. Therefore, the current work presented a novel nanocomposite that could be efficiently employed in various environmental and medical applications.

Sustainable adsorptive removal of antibiotic residues by chitosan composites: An insight into current developments and future recommendations

During COVID-19 crisis, water pollution caused by pharmaceutical residuals have enormously aggravated since millions of patients worldwide are consuming tons of drugs daily. Antibiotics are the preponderance pharmaceutical pollutants in water bodies that surely cause a real threat to human life and ecosystems. The excellent characteristics of chitosan such as nontoxicity, easy functionality, biodegradability, availability in nature and the abundant hydroxyl and amine groups onto its backbone make it a promising adsorbent. Herein, we aimed to provide a comprehensive overview of recent published research papers regarding the removal of antibiotics by chitosan composite-based adsorbents. The structure, ionic form, optimum removal pH and λ_max of the most common antibiotics including Tetracycline, Ciprofloxacin, Amoxicillin, Levofloxacin, Ceftriaxone, Erythromycin, Norfloxacin, Ofloxacin, Doxycycline, Cefotaxime and Sulfamethoxazole were summarized. The development of chitosan composite-based adsorbents in order to enhance their adsorption capacity, reusability and validity were presented. Moreover, the adsorption mechanisms of these antibiotics were explored to provide more information about adsorbate-adsorbent interactions. Besides the dominant factors on the adsorption process including pH, dosage, coexisting ions, etc. were discussed. Moreover, conclusions and future recommendations are provided to inspire for further researches.

Novel Biogenic Synthesis of a Ag@Biochar Nanocomposite as an Antimicrobial Agent and Photocatalyst for Methylene Blue Degradation

The conventional synthesis of nanomaterials employing physical and chemical methods usually requires high cost and toxic chemicals. Thus, a facile, ecofriendly, cost-effective, novel, and sustainable route for the synthesis of a silver-loaded biochar nanocomposite (Ag@biochar) using Chenopodium ambrosioides leaf extract and biomass is reported for the first time in this study to advocate many of the principles of green chemistry such as safer solvents and auxiliaries. UV spectroscopic analysis at 420 nm indicated the formation of silver nanoparticles (AgNPs). The band gap energy of Ag@biochar was 1.9 eV, confirming its potential use as a photocatalyst. Ag@biochar was found to be photoluminescent at 425 nm. AgNPs on the surface of biochar were predominantly spherical with a size range of 25-35 nm and a surface area of 47.61 m2/g. A zeta potential of -5.87 mV designated the stability of Ag@biochar. Testing the photocatalytic potential of Ag@biochar to remove methylene blue from wastewater demonstrated its high removal efficiency that reached 88.4% due to its high efficiency of electron transfer confirmed via electrochemical impedance spectroscopy analysis and retained 70.65% after six cycles of reuse. Ag@biochar was shown to be a powerful broad-spectrum antimicrobial agent as it completely prevented the growth of Escherichia coli and also inhibited the growth of Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis, and Candida albicans with the inhibition zones of 19, 18, 22, and 16 mm, respectively.

Facile Synthesis of Gold Nanoparticles for Anticancer, Antioxidant Applications, and Photocatalytic Degradation of Toxic Organic Pollutants

In the current study, a facile, rapid, and ecologically safe photosynthesis of gold nanoparticles (AuNPs) that remained stable for 3 months is reported to advocate the main aspects of green chemistry, such as safer solvents and auxiliaries, and the use of renewable feedstock. Zi-AuNPs were phytosynthesized by the aqueous extract of Ziziphus spina-christi leaves, and numerous techniques were employed for their characterization. The results demonstrated the successful phytofabrication of crystalline AuNPs with brownish-black color, spherical nanoparticles with a size between 0 and 10 nm, a plasmon peak at 540 nm, and a surface charge of -25.7 mV. Zi-AuNPs showed an effective photodegradation efficiency (81.14%) against malachite green and a good recycling capacity of 69.2% after five cycles of regeneration. The cytotoxicity test by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay signified a high anticancer efficiency for both Zi-AuNPs and Z. spina-christi extract against human breast cancer cells (MCF7 cell line) with IC₅₀'s of 48 and 40.25 μg/mL, respectively. Highly efficient antioxidant capabilities were proven with 2,2-diphenyl-1-picrylhydrazyl (DPPH) removal percentages of 67.5% for Zi-AuNPs and 92.34% for Z. spina-christi extract.

Comparative study among Avicennia marina, Phragmites australis, and Moringa oleifera based ethanolic-extracts for their antimicrobial, antioxidant, and cytotoxic activities

Microbial resistance and other emerging health risk problems related to the side effects of synthetic drugs are the major factors that result in the research regarding natural products. Fruits, leaves, seeds, and oils-based phyto-constituents are the most important source of pharmaceutical products. Plant extract chemistry depends largely on species, plant components, solvent utilized, and extraction technique. This study was aimed to compare the ethanolic extracts of a mangrove plant, i.e., Avicennia marina (1E: Lower half of A. marina‘s pneumatophores, 2E: A. marina‘s leaves, 3E: Upper half of A. marina‘s pneumatophores, and 4E: A. marina‘s shoots), with non-mangrove plants, i.e., Phragmites australis (5E: P. australis‘s shoot), and Moringa oleifera (6E: M. oleifera‘s leaves) for their antimicrobial activities, total phenolic contents, antioxidant activity, and cytotoxicity potential. The antimicrobial activity assays were performed on gram-positive bacteria (i.e., Bacillus subtilis and Staphylococcus aureus), gram-negative bacteria (i.e., Escherichia coli, and Pseudomonas aeruginosa), and fungi (i.e., Aspergillus niger, Candida albicans, and Rhizopus spp.). We estimated antioxidant activity by TAC, DPPH, and FRAP assays, and the cytotoxicity was evaluated by MTT assay. The results of antimicrobial activities revealed that B. subtilis was the most sensitive to the tested plant extracts compared to S. aureus, while it only showed sensitivity to 6E and Imipenem. 5E and 6E showed statistically similar results against P. aeruginosa as compared to Ceftazidime. E. coli was the most resistant bacteria against tested plant extracts. Among the tested plant extracts, maximum inhibition activity was observed by 6E against A. niger (22 ± 0.57 mm), which was statistically similar to the response of 6E against C. albicans and 3E against Rhizopus spp. 2E did not show any activity against tested fungi. We found that 6E (208.54 ± 1.92 mg g⁻¹) contains maximum phenolic contents followed by 1E (159.42 ± 3.22 mg g⁻¹), 5E (131.08 ± 3.10 mg g⁻¹), 4E (i.e., 72.41 ± 2.96 mg g⁻¹), 3E (67.41 ± 1.68 mg g⁻¹), and 2E (48.72 ± 1.71 mg g⁻¹). The results depict a significant positive correlation between the phenolic contents and the antioxidant activities. As a result, phenolic content may be a natural antioxidant source.

Catalytic and Medical Potential of a Phyto-Functionalized Reduced Graphene Oxide-Gold Nanocomposite Using Willow-Leaved Knotgrass

In the current study, a simple, environmentally friendly, and cost-effective reduced graphene oxide-gold nanoparticle (rGO-AuNP) nanocomposite was successfully phytosynthesized using the aqueous leaf extract of a common weed found on the Nile banks, Persicaria salicifolia, for the first time. The phytosynthesis of rGO-AuNPs was first confirmed via the color transformation from brown to black as well as throughvarious techniques such as transmission electron microscopy (TEM) and Raman spectroscopy. Two UV-vis peaks at 275 and 530 nm were observed for the nanocomposite with a typical particle size of mostly spherical AuNPs of 15-20 nm. However, other shapes were occasionally detected including rods, triangles, and rhomboids. Existing phytoconstituents such as flavonoids and glycosides in the plant extract were suggested to be responsible for the phytosynthesis of rGO-AuNPs. The excellent catalytic efficacy of rGO-AuNPs against MB degradation was confirmed, and a high antibacterial efficiency against Escherichia coli and Klebsiella pneumonia was also confirmed. Promising antioxidant performance of rGO-AuNPs was also proved. Furthermore, it was concluded that rGO-AuNPs acquired higher efficiency than AuNPs synthesized from the same plant extract in all of the studied applications.

Green Synthesis of Metal and Metal Oxide Nanoparticles Using Different Plants’ Parts for Antimicrobial Activity and Anticancer Activity: A Review Article

Nanotechnology emerged as a scientific innovation in the 21st century. Metallic nanoparticles (metal or metal oxide nanoparticles) have attained remarkable popularity due to their interesting biological, physical, chemical, magnetic, and optical properties. Metal-based nanoparticles can be prepared by utilizing different biological, physical, and chemical methods. The biological method is preferred as it provides a green, simple, facile, ecofriendly, rapid, and cost-effective route for the green synthesis of nanoparticles. Plants have complex phytochemical constituents such as carbohydrates, amino acids, phenolics, flavonoids, terpenoids, and proteins, which can behave as reducing and stabilizing agents. However, the mechanism of green synthesis by using plants is still highly debatable. In this report, we summarized basic principles or mechanisms of green synthesis especially for metal or metal oxide (i.e., ZnO, Au, Ag, and TiO2, Fe, Fe2O3, Cu, CuO, Co) nanoparticles. Finally, we explored the medical applications of plant-based nanoparticles in terms of antibacterial, antifungal, and anticancer activity.

Green Synthesis of Nano-Zero-Valent Iron Using Ricinus Communis Seeds Extract: Characterization and Application in the Treatment of Methylene Blue-Polluted Water

In this study, the removal of methylene blue dye (MB) from aqueous solution was examined using a novel green adsorbent to overcome the obstacles encountered in chemical methods. Ricinus communis (RC) aqueous seeds extract was herein used as a reducing and capping agent to synthesize a novel nano-zero-valent iron (RC-nZVI) for the adsorption of harmful MB. Structural and morphological characterization of the synthesized RC-nZVI were performed using several techniques, e.g., steady-state absorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and zeta potential. The maximum efficiency of the removal was 96.8% at pH 6 and 25 °C. According to the kinetics study results, the adsorption process obeys the pseudo-first-order model. The experimental equilibrium data were fitted to the Freundlich isotherm model, the maximum adsorption capacity reached was 61.37 mg·g-1, and the equilibrium parameters were determined. The synthesized RC-nZVI possesses good reusability and can be considered as a potential economic and environmentally friendly adsorbent.

Highly Efficient Removal for Methylene Blue and Cu2+ onto UiO-66 Metal-Organic Framework/Carboxylated Graphene Oxide-Incorporated Sodium Alginate Beads

Herein, we report a new metal-organic framework (MOF)-based composite beads adsorbent made via incorporating UiO-66 MOF, carboxylated graphene oxide (GOCOOH) into sodium alginate for efficient removal of methylene blue dye, and Cu2+ ions. The successful fabrication of the synthesized UiO-66/GOCOOH@SA composite beads was confirmed by means of X-ray diffraction, Fourier transform infrared, scanning electron microscopy, zeta potential, X-ray photoelectron spectroscopy analysis, and thermogravimetric analysis and BET measurement. The incorporation of both UiO-66 and GOCOOH into SA beads greatly increased their adsorption efficiency for the removal of both MB and Cu2+ with maximum adsorption capacities of 490.72 and 343.49 mg/g, respectively. The removal process of both MB and Cu2+ follows the pseudo-second-order model and Freundlich isotherm model. A plausible adsorption mechanism was discussed in detail. Regeneration tests clarified that the removal efficiencies toward both MB and Cu2+ remained higher than 87% after five cycles. These results reveal the potentiality of UiO-66/GOCOOH@SA beads as an excellent adsorbent.