Green Synthesis Of Metal Research Articles

Plant‐Based Biosynthesis of Metal and Metal Oxide Nanoparticles: An Update on Antimicrobial and Anticancer Activity

AbstractNanotechnology has changed and developed all the sectors and working fields. Nanoparticles are one of the important evolutionary materials that have application in almost all the working areas such as catalysis, bioengineering, photoelectricity, antibacterial, anticancer, and medical imaging due to their unique physical and chemical properties. Traditionally used chemical and physical method of synthesis of nanoparticles have several disadvantages like using different chemicals, high cost, and most importantly they are hazardous to the environment. Counter to these disadvantages, a more eco‐friendly, easy, and cost‐effective green synthesis method is widely employed nowadays. Various parts of a plant are used as a fuel for reducing the metal ion salt. Plant extracts act as reducing, stabilizing, and capping agents. Besides these advantages, photosynthesized nanoparticles are nontoxic, more stable, and more uniform in size than their counterparts prepared by the traditional method. In this present review, the synthesis of various plant extract‐mediated metal and metal oxide nanoparticles is discussed along with their different applications. This review provides a comprehensive overview of key findings in green synthesis of metal and metal oxide nanoparticles and attempts to determine their possible synthesis mechanism. This article also focuses on factors affecting their synthesis, characterization, potential applications, and prospects.

Green-synthesized Metal Nanoparticles for Cancer Diagnosis and Treatment: A Critical Review

: The utilization of chemotherapy remains an established therapeutic strategy in the ongoing fight against cancer. Nevertheless, it has been impeded by the occurrence of several fatal adverse reactions caused by non-specific toxicity often associated with chemotherapy. Nanotechnology is an emerging field of research that is experiencing rapid growth and is widely recognized as a highly promising approach for advanced cancer therapy. Biosynthesized green nanomaterials are emerging as promising tools for cancer treatment and diagnosis. Metal nanoparticles have been developed for use in several applications, including magnetically sensitive medication delivery, photothermal treatment, and photoimaging. Nanomaterials containing metals, such as iron, cobalt, and silver, which are generated from various bio-sources, have been described. The boundless capabilities of nanoparticles have already had a profound impact on human existence. Nevertheless, the potential adverse effects of nanoparticles on human health have consistently instilled apprehension. A thorough investigation of the toxicity and intricate nature of nanomaterials has facilitated the emergence of nanotoxicology, a field that examines the fundamental origins of these problems. The introduction of green chemistry principles has aimed to provide safer techniques for the production and management of nanomaterials, resulting in the emergence of green nanotechnology. This review article highlights the potential uses of green nanotechnology for the detection and management of tumors, including the challenges they face in reaching clinical trials.

Harnessing Bacterial Consortia and Green-Synthesized Metal Oxide Nanoparticles for Photocatalytic Dye Degradation

Harnessing Bacterial Consortia and Green-Synthesized Metal Oxide Nanoparticles for Photocatalytic Dye Degradation

Anabaena sp. A-1 mediated molybdenum oxide nanoparticles: A novel frontier in green synthesis, characterization and pharmaceutical properties.

Green-synthesized metal oxide nanoparticles have garnered considerable attention due to their simple, sustainable, and eco-friendly attributes, coupled with their diverse applications in biomedicine and environmental context. The current study shows a sustainable approach for synthesizing molybdenum oxide nanoparticles (MoONPs) utilizing an extract from Anabaena sp. A-1. This novel approach marks a significant milestone as various spectral approaches were employed for characterization of the green-synthesized MoONPs. Ultraviolet-visible (UV-Vis) spectroscopic analysis revealed a surface plasmon resonance (SPR) peak of MoONPs at 538 nm. Fourier transform infrared (FTIR) spectral analysis facilitated the identification of functional groups responsible for both the stability and production of MoONPs. Scanning electron microscopy (SEM) was utilized revealing a rod shape morphology of the MoONPs. X-ray diffraction (XRD) analysis yielded a calculated crystal size of 31 nm, indicating the crystalline nature of MoONPs. Subsequently, biological assays were employed to ascertain the potential of the bioengineered MoONPs. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to quantify free radical scavenging activity, revealing an antioxidant capacity of 68.1% at 200 μg/mL. To evaluate antibacterial and antifungal efficacy, the disc diffusion method was employed across varying concentrations of MoONPs (6.25, 12.5, 25, 50, 100, 150, 200 μg/mL). Quantification of cytotoxicity was performed via a brine shrimp assay, yielding an IC50 value of 552.3 μg/mL, a metric of moderate cytotoxicity. To assess the biocompatibility of MoONPs, an antihemolytic assay was conducted, confirming their safety profile. Additionally, MoONPs exhibited non-toxic attributes in an insecticidal assay. Notably, in anti-inflammatory assay MoONPs showed an inactive nature towards the reactive oxygen species. In conclusion, these findings highlight the potential versatility of MoONPs in various biological applications, extending beyond their recognized anti-inflammatory and insecticidal properties. RESEARCH HIGHLIGHTS: This study marks an advancement in nanotechnology, exploring ways for MoONPs fabrication, representing a unique and unexplored research domain. Green-synthesized MoONPs using Anabaena sp. A-1 extract offers a sustainable and eco-friendly approach. Characterized by UV-Vis, FTIR, SEM, and XRD, MoONPs demonstrate rod-shaped morphology and crystalline nature. Bioengineered MoONPs exhibit versatility in biological applications, demonstrating notable antioxidant, antibacterial and antifungal efficacy, moderate cytotoxicity, biocompatibility, and insecticidal properties, emphasizing their multifaceted utility. The research findings highlight the potential utilization of MoONPs across a spectrum of biological applications, thereby suggesting their promising role in the realm of biomedicine and environmental context.

Physical characterization, biocompatibility, and antimicrobial activity of polyvinyl alcohol/sodium alginate blend doped with TiO2 nanoparticles for wound dressing applications

The ability of wound dressing materials to tackle skin pathogens colonization that is associated with open wound infections is limited. Recently, green-synthesized metal oxide nanoparticles has received a lot of attention to overcome this limitation. However, titanium dioxide nanoparticles (TiO2-NPs) exhibit exceptional antibacterial properties. In this work, several concentrations (0, 1, 3, and 5 wt.%) of TiO2 NPs prepared using Aloe vera leaf extract were added to a blend of polyvinyl alcohol and sodium alginate (PVA:SA). This nanocomposite was designed to enhance the healing process of wounds. The interaction between the PVA:SA composite and the TiO2 NPs was confirmed by FTIR. The thermal behavior of the nanocomposite films was investigated using DSC and TGA. The experimental results indicate that the glass transition temperatures of the nanocomposites increased by increasing the added amount of TiO2 NPs to be 53.7 °C (1 wt.%), 55.8 °C (3 wt.%), and 60.6 °C (5 wt.%), which were consistently lower than the glass transition temperature of the matrix material (69.6 °C). The Dynamic Mechanical Analysis was examined. The nanocomposite doped with 5 wt.% of TiO2 NPs detected a high storage modulus (21.6 × 108). Based on swelling and degradation studies, the prepared PVA:SA:TiO2 nanocomposite films have an excellent swelling rate, and the inclusion of TiO2 NPs increases the stability of the polymeric matrix. The PVA:SA:TiO2 nanocomposite films exhibited a superior antibacterial efficacy against Gram-positive bacteria such as Bacillus cereus and Staphylococcus aureus, compared to their effectiveness against Gram-negative bacteria like Escherichia coli. Moreover, the nanocomposite films were biocompatible with Human Skin Fibroblast. Therefore, the developed PVA:SA:TiO2 nanocomposite films suit wound dressing applications.

Fabrication and characterization of a novel strontium oxide-polythiophene core–shell nanocomposite for in-vitro electrochemical detection of antiplatelet cilostazol drug in formulation and human plasma

The green synthesis of metal or metal oxide nanoparticles utilizing plants is a novel promising approach in bio-nanotechnology. The strontium oxide nanoparticles (SrO NPs) were synthesized for the first time utilizing a plant extract of Green cardamom (Elettaria cardamomum) as a reducing and stabilizing agent. The strontium oxide polythiophene (SrO@PTh) nanocomposite was then prepared by in-situ oxidative polymerization of thiophene on the surface of SrO NPs using anhydrous FeCl3 as an oxidant. FTIR spectrum indicates the coordination of SrO NPs with the binding sites along PTh backbone. TEM analysis resulted in an average particles size of (25 – 50 nm) for SrO NPs and core–shell nanostructure of its composite (SrO@PTh CS) with shell thickness of (20–90 nm). The XRD analysis indicates a crystalline cubic structure of SrO NPs with particles size of ≈ 45 nm in average and interplanar space of (0.24 ∼ 0.36 nm). The crystallinity was relatively diminished to some extent for SrO@PTh CS which exhibits a particle size of about 85 nm and interplanar space of (0.13 ∼ 0.23 nm). A smart and novel electrochemical graphite paste sensor (GPS), based on SrO@PTh CS nanocomposite, has been fabricated for the ultrasensitive in-vitro detection of antiplatelet drug cilostazol. SrO@PTh CS nanocomposite-based square-wave voltammetry biosensor exhibited the lowest limits of detection of 1.99 × 10−10 and 9.83 × 10−10 M for cilostazol drug determination in bulk and human plasma samples, respectively compared to all the reported methods. It exhibited also good reproducibility, repeatability, long-term stability and was free from biological interference effects.

Green synthesis of silver nanoparticles derived from lemon and pomegranate peel extracts to combat multidrug-resistant bacterial isolates

BackgroundMultidrug-resistant (MDR) bacteria are acknowledged as one of the main factors contributing to chronic illnesses and fatalities globally. Numerous diseases, including bloodstream infections, pneumonia, urinary tract infections, and surgical site infections, can be brought on by MDR bacteria. Therefore, a crucial topic of continuing research is the development of a novel and different treatment for MDR microbial pathogens. This work is introduce an alternative method for elimination of MDR bacterial isolates which are causative agents of urinary tract infection among people in Egypt. In our study, we need a novel strategy to combat MDR bacteria by green-synthesized metal nanoparticles (MNPs). That is due to the ability of MNPs to penetrate the cell wall and the cell membrane of gram-positive and gram-negative bacteria. MethodsClinical isolates of MDR bacteria had their antibiotic susceptibility assessed before being molecularly identified using 16 s rRNA, sequencing, and phylogenetic analysis. Also, genetic profiles of isolated strains were performed using ISSR and SDS-PAGE. Finally, characterized plant-mediated silver nanoparticles derived from lemon and pomegranate peel extracts were evaluated against isolated multidrug-resistant bacterial stains. ResultsIn our present trial, one-hundred urine samples were collected from 71 females and 29 males complaining of UTI (urinary tract infection) symptoms. One-hundred microbial isolates were isolated, including 88-g negative and only 8-g positive bacteria in addition to four yeast isolates (Candida species). A total of 72% of the isolated bacteria showed MDR activity. The most prevalent MDR bacterial isolates (Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, and Klebsiella pneumoniae) were identified through 16S rDNA PCR sequencing as with accession numbers OP741103, OP741104, OP741105, OP741106, and OP741107, respectively. Lemon and pomegranate-mediated silver nanoparticles [Ag-NPs] were characterized by UV spectroscopy, FTIR, XRD, and TEM with average size 32 and 28 nm, respectively. Lemon and pomegranate-mediated silver nanoparticles [Ag-NPs] showed an inhibitory effect on the selected five MDR isolates at MIC 50 and 30 µg/mL, respectively. These common bacterial isolates were also genetically examined using ISSR PCR, and their total protein level was evaluated using SDS-PAGE, showing the presence of distinct genetic and protein bands for each bacterial species and emphasizing their general and protein composition as a crucial and essential tool in understanding and overcoming MDR behavior in UTI patients. ConclusionsLemon and pomegranate-mediated silver nanoparticles [Ag-NPs] were found to have an inhibitory effect on MDR isolates. Therefore, the study suggests that [Ag-NPs] could be a potential treatment for MDR UTI infections caused by the identified bacterial species.

Applications of Green Synthesized Metal Nanoparticles - a Review.

Green nanotechnology is an emerging field of science that focuses on the production of nanoparticles by living cells through biological pathways. This topic plays an extremely imperative responsibility in various fields, including pharmaceuticals, nuclear energy, fuel and energy, electronics, and bioengineering. Biological processes by green synthesis tools are more suitable to develop nanoparticles ranging from 1 to 100nm compared to other related methods, owing to their safety, eco-friendliness, non-toxicity, and cost-effectiveness. In particular, the metal nanoparticles are synthesized by top-down and bottom-up approaches through various techniques like physical, chemical, and biological methods. Their characterization is very vital and the confirmation of nanoparticle traits is done by various instrumentation analyses such as UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), atomic force microscopy (AFM), annular dark-field imaging (HAADF), and intracranial pressure (ICP). In this review, we provide especially information on green synthesized metal nanoparticles, which are helpful to improve biomedical and environmental applications. In particular, the methods and conditions of plant-based synthesis, characterization techniques, and applications of green silver, gold, iron, selenium, and copper nanoparticles are overviewed.

Evaluation of Nanomedicine Applications of Silver and Zinc Oxide Nanoparticles Using Water Extract of Fresh Turmeric

Recently, there has been a lot of research into the green synthesis of metal and metal oxide nanoparticles, particularly from plants. To date, however, there has been no published study detailing the synthesis of Ag and ZnO nanoparticles using fresh turmeric extract. In this experiment, silver and zinc oxide nanoparticles were synthesised with an environmentally friendly capping and reducing agent made from fresh turmeric extracts. The synthesised Ag and ZnO nanoparticles were verified using UV–vis, FT-IR, XRD, TGA, HR-SEM, and HR-TEM. The SEM and XRD showed that the synthesised nanoparticles had a size range of 10–30 nm, a highly crystalline form, and a well-almost spherical shape. Medical applications for the synthesised Ag and ZnO nanoparticles include their antibacterial activity against S. aureus and Klebsiella pneumonia. Scavenging activities varied from 20% to 70% for turmeric, 0% to 20% for ZnO, and 40% to 60% for silver. ZnO was found to be more cytotoxic than Ag against THP-I at the tested concentrations. Overall, the biologically synthesised silver and zinc oxide presented in this study offers a safe alternative to synthetic substances and shows promise as a candidate for antimicrobial, antioxidant, and cytotoxic activity in nanomedicine.

Plasma-Chemical Synthesis and Properties of Oxide Compounds of Cobalt

To date, the possibilities of using metal oxide particles in various fields have been developed [1]. At the same time, their characteristics largely depend on the method of preparation, which usually determines their structure, size, and physicochemical properties [2].Among the methods for obtaining nanosized particles, one can single out methods of green synthesis [3], electrochemical [4], electropulse [5], and plasmachemical [6] synthesis based on the reduction or oxidation of metal ions in solutions under favorable conditions, followed by aggregation of nanoparticles.The purpose of this work is to analyze the technology for the synthesis of cobalt oxide compounds using contact nonequilibrium low-temperature plasma and to determine the directions for its further improvement.The object of the study was the process of obtaining particles of cobalt oxide using contact non-equilibrium low-pressure plasma during the processing of a liquid medium.The study was carried out using laboratory equipment and software modules of the HSC Chemistry 5.11 package. To find the preliminary conditions for the formation of interphase boundaries, diagrams were used in the coordinates of the E-pH potential of the aquatic environment (Pourbaix diagrams). It has been established that, depending on the initial state of Co(OH)2 in solution, the mass fraction of oxygen in the precipitate can change. In this case, the addition of hydrogen peroxide leads to a decrease in the proportion of hydroxide compounds in sediments. X-ray phase analysis showed the presence of CoO, CoOOH, Co3O4, β-Co(OH)2, Co in dry sediments. It has been established that the particle sizes lie in the range of 10 – 110 nm. The micrographs confirm the agreement between the calculated values and the experimental data.The phase composition of the deposit is influenced by the following factors: current density and anion concentration, process temperature. Increasing the temperature increases the diffusion coefficient but requires a higher current density to produce a powder. It has been established that a decrease in the liquid layer contributes to an increase in the yield of oxide compounds. The results of the analysis allow us to conclude that when using the technologies of plasma-chemical processing of liquid media to obtain compounds of the ultra- and nanoscale range, it becomes necessary to choose the parameters that are optimal for this process. The results of the analysis allow us to conclude that this technology can be optimized by controlling the initial pH of the solution; use of the spent solution in a container with the initial solution for its acidification; refinement of the reactor block for treating the solution in a film mode or close to it; choice of rational parameters for sludge drying. Laurent S., Boutry S., Muller R. N. Metal oxide particles and their prospects for applications //Iron oxide nanoparticles for biomedical applications. – Elsevier, 2018. –P. 3-42.Wang L. et al. Rational design, synthesis, adsorption principles and applications of metal oxide adsorbents: a review //Nanoscale. – 2020. – Vol. 12. – №. 8. – P. 4790-4815.El Shafey A. M. Green synthesis of metal and metal oxide nanoparticles from plant leaf extracts and their applications: A review //Green Processing and Synthesis. – 2020. – Vol. 9. – №. 1. – P. 304-339.Lawrence M. J., Kolodziej A., Rodriguez P. Controllable synthesis of nanostructured metal oxide and oxyhydroxide materials via electrochemical methods //Current Opinion in Electrochemistry. – 2018. – Vol. 10. – P. 7-15.Gan Z. et al. A laser and electric pulse modulated nonvolatile photoelectric response in nanoscale copper dusted metal‐oxide‐semiconductor structures //Advanced Electronic Materials. – 2018. – Vol. 4. – №. 11. – P. 1800234.Shamanin I. et al. Plasmachemical synthesis and evaluation of the thermal conductivity of metal-oxide compounds for prospective nuclear fuel //Journal of Physics: Conference Series. – IOP Publishing, 2019. – Vol. 1145. – №. 1. – P. 012057.

Green Synthesis and Characterization of ZnO Nanoparticles Using Pelargonium odoratissimum (L.) Aqueous Leaf Extract and Their Antioxidant, Antibacterial and Anti-inflammatory Activities.

Nanoparticles (NPs) exhibit distinct features compared to traditional physico-chemical synthesis and they have many applications in a wide range of fields of life sciences such as surface coating agents, catalysts, food packaging, corrosion protection, environmental remediation, electronics, biomedical and antimicrobial. Green-synthesized metal NPs, mainly from plant sources, have gained a lot of attention due to their intrinsic characteristics like eco-friendliness, rapidity and cost-effectiveness. In this study, zinc oxide (ZnO) NPs have been synthesized employing an aqueous leaf extract of Pelargonium odoratissimum (L.) as a reducing agent; subsequently, the biosynthesized ZnO NPs were characterized by ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). Moreover, aqueous plant leaf extract was subjected to both qualitative and quantitative analysis. Antioxidant activity of ZnO NPs was assessed by DPPH assay, with varying concentrations of ZnO NPs, which revealed scavenging activity with IC50 = 28.11 μg mL−1. Furthermore, the anti-bacterial efficacy of the green synthesized ZnO NPs against four foodborne pathogenic bacterial strains was examined using the disk diffusion assay, and Staphylococcus aureus (ATCC 8095), Pseudomonas aeruginosa (ATCC10662) and Escherichia coli (ATCC 25922) were found to be the most sensitive against biosynthesized ZnO NPs, whereas the least sensitivity was shown by Bacillus cereus (ATCC 13753). The anti-inflammatory effect was also evaluated for both ZnO NPs and the aqueous leaf extract of P. odoratissimum through the human red blood cells (HRBC) membrane stabilization method (MSM) in vitro models which includes hypotonicity-induced hemolysis. A maximum membrane stabilization of ZnO NPs was found to be 95.6% at a dose of 1000 μg mL−1 compared with the standard indomethacin. The results demonstrated that leaf extract of P. odoratissimum is suitable for synthesizing ZnO NPs, with antioxidant, antibacterial as well as superior anti-inflammatory activity by improving the membrane stability of lysosome cells, which have physiological properties similar to erythrocyte membrane cells and have no hemolytic activity. Overall, this study provides biosynthesized ZnO NPs that can be used as a safe alternative to synthetic substances as well as a potential candidate for antioxidants, antibacterial and anti-inflammatory uses in the biomedical and pharmaceutical industries.

The Potential Application of Green-Synthesized Metal Nanoparticles in Dentistry: A Comprehensive Review.

Orodental problems have long been managed using herbal medicine. The development of nanoparticle formulations with herbal medicine has now become a breakthrough in dentistry because the synthesis of biogenic metal nanoparticles (MNPs) using plant extracts can address the drawbacks of herbal treatments. Green production of MNPs such as Ag, Au, and Fe nanoparticles enhanced by plant extracts has been proven to be beneficial in managing numerous orodental disorders, even outperforming traditional materials. Nanostructures are utilized in dental advances and diagnostics. Oral disease prevention medicines, prostheses, and tooth implantation all employ nanoparticles. Nanomaterials can also deliver oral fluid or pharmaceuticals, treating oral cancers and providing a high level of oral healthcare. These are also found in toothpaste, mouthwash, and other dental care products. However, there is a lack of understanding about the safety of nanomaterials, necessitating additional study. Many problems, including medication resistance, might be addressed using nanoparticles produced by green synthesis. This study reviews the green synthesis of MNPs applied in dentistry in recent studies (2010–2021).

Nanoforms of essential metals: from hormetic phytoeffects to agricultural potential.

Vital plant functions require at least six metals (copper, iron, molybdenum, manganese, zinc, and nickel), which function as enzyme cofactors or inducers. In recent decades, rapidly evolving nanotechnology has created nanoforms of essential metals and their compounds (e.g. nZnO, nFe2O3) with a number of favourable properties over the bulk materials. The effects of nanometals on plants are concentration-dependent (hormesis) but also depend on the properties of the nanometals, the plant species, and the treatment conditions. Here, we review studies examining plant responses to essential nanometal treatments using a (multi)omics approach and emphasize the importance of gaining a holistic view of the diverse effects. Furthermore, we discuss the beneficial effects of essential nanometals on plants, which provide the basis for their application in crop production as, for example, nanopriming or nanostimulator agents, or nanofertilizers. As lower environmental impact and increased yield can be achieved by the application of essential nanometals, they support sustainable agriculture. Recent studies have actively examined the utilization of green-synthesized metal nanoparticles, which perfectly fit into the environmentally friendly trend of future agriculture. Further knowledge is required before essential nanometals can be safely applied in agriculture, but it is a promising direction that is timely to investigate.

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 Metal and Metal Oxide Nanoparticles: Principles of Green Chemistry and Raw Materials

Increased request for metal and metal oxide nanoparticles nanoparticles has led to their large-scale production using high-energy methods with various toxic solvents. This cause environmental contamination, thus eco-friendly “green” synthesis methods has become necessary. An alternative way to synthesize metal nanoparticles includes using bioresources, such as plants and plant products, bacteria, fungi, yeast, algae, etc. “Green” synthesis has low toxicity, is safe for human health and environment compared to other methods, meaning it is the best approach for obtaining metal and metal oxide nanoparticles. This review reveals 12 principles of “green” chemistry and examples of biological components suitable for “green” synthesis, as well as modern scientific research of eco-friendly synthesis methods of magnetic and metal nanoparticles. Particularly, using extracts of green tea, fruits, roots, leaves, etc., to obtain Fe3O4 NPs. The various precursors as egg white (albumen), leaf and fruit extracts, etc., can be used for the „green” synthesis of spinel magnetic NPs. “Green” nanoparticles are being widely used as antimicrobials, photocatalysts and adsorbents. “Green” magnetic nanoparticles demonstrate low toxicity and high biocompatibility, which allows for their biomedical application, especially for targeted drug delivery, contrast imaging and magnetic hyperthermia applications. The synthesis of silver, gold, platinum and palladium nanoparticles using extracts from fungi, red algae, fruits, etc., has been described.

Dual Synthesis of Silver and Iron Oxide Nanoparticles from Edible Green Amaranthus Viridis and their In vitro Antioxidant Activity and Antimicrobial Studies

Background: There is an increasing commercial demand for nanoparticles due to their wide applicability in various areas, such as chemistry, catalysis, energy and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques where the chemicals used are quite often toxic and flammable. Objective: In the present study, we have described a simple, cost-effective and environmentally- friendly technique for green synthesis of silver and iron nanoparticles by using the aqueous extract of leafy vegetable Amaranthus viridis as a reducing agent. Methods: The silver and iron nanoparticles (Av-AgNPs, Av-IONPs) were characterized by different spectral methods. The surface plasmon resonance spectrums of Av-AgNPs, Av-IONPs were recorded at 422nm and 261nm. The scanning electron microscopy (SEM) analysis reveals that the Av-AgNPs and Av-IONPs are roughly spherical in shape. Energy dispersive absorption spectroscopy (EDAX) of biosynthesized Av-AgNPs and Av-IONPs indicates the reduction of silver ions to elemental silver and iron ions to elemental iron. Results: The particle size analysis of Av-AgNPs and Av-IONPs was carried out by the dynamic light scattering (DLS) method; the results reveal both Av-AgNPs and Av-IONPs to be polydispersed in nature. The average particle size of Av-AgNPs is 55.8 nm with a polydispersed index (PI) of 0.297; similarly, the average particle size of Av-IONPs is 80.6 nm with a polydispersed index (PI) of 0.469. Zeta-potential of Av-AgNPs was detected at -24.6 mV and Av-IONPs were detected at 28.8 mV; the result reveals that their high stability may be due their high negative charge and positive charge, respectively. The dual synthesized Av-AgNPs and Av-IONPs exhibited excellent antioxidant activity by DPPH, H2O2 and NO methods. DPPH was proven to be the best when compared with the other two methods. The biosynthesized Av-AgNPs and Av-IONPs proved to have very good antimicrobial activity against gram +ve and gram –ve bacteria. Conclusion: Compared with the standard antibiotic, there are several reports on the green synthesis of metal nanoparticles using various plant parts, but here, edible leafy vegetable Amaranthus viridis was used for biosynthesis of both Av-AgNPs and Av-IONPs.

Genotoxic assay of silver and zinc oxide nanoparticles synthesized by leaf extract of Garcinia livingstonei T. Anderson: A comparative study

Background: Green synthesis of metal and metal oxide nanoparticles (NPs) using plant extract performs a significant role as it is a promising alternative to the conventional chemical method in nanotechnology. Aims: In this paper, we report an environmentally benign method for the synthesis of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) using leaf extract of Garcinia livingstonei, and their mitotic activities were investigated using the root tip of Cicer arietinum. Objectives: The as-prepared NPs were characterized by ultraviolet-visible spectroscopy, infrared spectroscopy (FT-IR), X-ray diffraction (XRD), atomic force microscopy (AFM), and high-resolution transmission electron microscopy (HR-TEM). Analysis of FT-IR spectrum revealed that certain functional groups behaved as reducing and stabilizing agents in the formation of nanostructures. The crystalline nature of the AgNPs and ZnONPs was confirmed by XRD analysis. The size and shape of the as-obtained materials were found using HR-TEM analysis and were in the range of 5–65 nm and 38–94 nm for AgNPs and ZnONPs, respectively. Further, the root cells of C. arietinum were treated with both AgNPs and ZnONPs in different concentrations (5, 25, 50, and 100 μg/ml) for 24 h at the interval of 3, 6, 12, and 24 h along with distilled water as control. Results: The study clearly indicated that the AgNPs and ZnONPs showed an inhibitory effect on the cell division in root tip cells and caused a decrease in their mitotic index (MI) values. The reduction in MI in AgNPs is more evident than that of ZnONPs when compared to control. Aberrations in chromosomal behavior such as micronucleus, sticky chromosomes, bridges, multipolar anaphase, laggard, and c-metaphase were also observed. Conclusion: From the results, it is evident that the percentage of MI is inversely proportional, and chromosomal aberrations (CAs) are directly proportional to the concentration and duration of exposure.

A Review on Green Synthesis of Metal and Metal Oxide Nanoparticles

A Review on Green Synthesis of Metal and Metal Oxide Nanoparticles

Pharmaceutical and Biomedical Applications of Green Synthesized Metal and Metal Oxide Nanoparticles.

Due to the rapid growth in life threatening diseases such as cancer, diabetes, chronic wound and HIV/AIDS along with rise of side effects of the current treatments, world is now focusing to utilize new treatment options. Currently, the development of green nanotechnology field seems as a potential alternate for diseases diagnosis and treatment by preparation of various sizes and shapes of nanomaterials. This review is to present the explored biological sources in synthesis of nanomaterials particularly metal and metal oxides nanoparticles and critical review of the applications of biosynthesized nanoparticles in pharmaceutical and biomedical fields. In this review, the various biological sources including bacteria, fungi, algae and plants used in synthesis of nanomaterials and mechanism involved in preparation are elaborated. In addition, biosynthesized nanomaterials applied as drug delivery system for anticancer, antibiotic, antidiabetic agent and functioned as potential diagnostic, antimicrobial, anticancer and wound healing candidates are comprehensively reviewed. The synthesized metal and metal oxides from green protocol proved to have advantages such as being biocompatible, effective and cheap. Furthermore, the green synthesized metal and metal oxide nanoparticles showed to possess prominent physical, chemical and biological properties that can be efficiently utilized for pharmaceutical and biomedical applications. The information gathered in this review will provide a baseline for exploring more potential usage of green synthesized metal and metal oxide nanomaterials for various other applications. However, a concrete understanding of the safety of these nanomaterials is still needed to minimize the potential side effects.

Magnesium oxide biosynthesized with Camellia sinensis extract as activator in nitrile rubber vulcanization

Green synthesis of metal and metal oxides is an emerging area in the field of technology and provides economic and environmental benefits as an alternative to physical and chemical processes. In this method, non-toxic reagents that are ecologically correct and safe are used. In this work, MgO was synthesized from the aqueous green tea (Camellia sinensis) extract and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy, which revealed the formation of MgO with face-centered cubic crystalline structure of crystallite size of 15.92 nm. Later, the green MgO obtained was used as activator in nitrile rubber compositions, replacing the industrially used ZnO as a vulcanization activator, and also compared to a commercial MgO. The evaluation was performed regarding the rheometric properties, the kinetic of vulcanization and crosslink density formation. The results obtained were promising both for the synthesis and application of MgO produced via the green route in elastomeric NBR compositions.