Reduced graphene oxide based iron oxide modified titania (rGO-Fe3O4/TiO2) was developed as a low-cost, stable, and reproducible photocatalyst, synthesized by conventional hydrothermal route. Structural and morphological features were investigated by X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). The incorporation of rGO-Fe3O4 to TiO2 shifted the light absorption of TiO2 from ultraviolet (UV) to visible region. The band gap energy of the synthesized photocatalyst rGO-Fe3O4/TiO2 reduced to 2.6 eV as compared to TiO2 (3.2 eV) which shifted the light absorption into visible region in order to utilize the solar energy effectually. The as-proposed rGO-Fe3O4/TiO2 and TiO2 photocatalysts were used for the photo-degradation of malachite green (MG) and methylene blue (MB) degradation. The as-prepared photocatalyst rGO-Fe3O4/TiO2 exhibited commendable photocatalytic efficiency (99%) comparative to pure TiO2 (67%) under visible light in 55 min for MG degradation. The active species were also identified using various scavengers by trapping holes and radicals generated during the photocatalytic degradation process. Subsequently, such photo-degradation output inferred that this ternary nanocomposite partakes a great potential for visible light driven MG and MB photocatalytic degradation.

Photocatalytic degradation of malachite green and methylene blue over reduced graphene oxide (rGO) based metal oxides (rGO-Fe3O4/TiO2) nanocomposite under UV-visible light irradiation

Multifunctional ZnO nanoparticles bio-fabricated from Canna indica L. flowers for seed germination, adsorption, and photocatalytic degradation of organic dyes.

Background Abelmoschus esculentus (L.) Moench, an economically important malvaceous vegetable crop popularly known as okra, is used in various culinary preparations and is rich in vitamins, minerals, and nutrients. The biological properties of okra flowers in relation to nanoparticle synthesis have not yet been reported. Materials and methods In the current study, silver nanoparticles (AgNPs) were synthesized using extracts of the flowers of A. esculentus. The characteristics of the AgNPs were studied using a UV-vis spectrometer, Fourier transmission infrared spectrophotometer (FTIR), X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectrometer (EDX). Antibacterial activity screening was performed using the agar well diffusion method, and cytotoxicity and cell viability studies were conducted using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results The synthesized AgNPs were spherical and ranged in size from 5.52 to 31.96 nm, with an average size of 16.19 nm, as determined by UV-vis spectroscopy, FTIR, XRD, TEM and EDX. A. esculentus flower extract-mediated silver nanoparticles (AME-AgNPs) exhibited excellent activities in vitro studies, particularly in vitro cytotoxic and antiproliferative studies against cancer cell lines, such as the TERT-4 and A-549 cell lines. The antibacterial effects on the Gram-positive pathogens Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes and the Gram-negative pathogens Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhimurium and Shigella sonnei were tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values varied with the bacterial strain. The IC50 values of the synthesized NPs for the tested cell lines were close to that of a standard drug. Conclusion Compared to other NPs the NPs synthesized in this study were smaller in size and exhibited a higher level of antibacterial activity, cytotoxicity and apoptosis at minimal concentrations, and this is the first study on okra flower-induced anticancer and antimicrobial activities.

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Green Synthesis of Silver Nanoparticles Using the Flower Extract of Abelmoschus esculentus for Cytotoxicity and Antimicrobial Studies.

Chemical pollutants released from textile industries are becoming a major concern for water pollution, causing hazardous diseases around the globe. Strategies developed against the treatment of effluents from textile industries are becoming a mere failure. Therefore, metal oxide nanoparticles (MO NPs) came into rescue as an alternative to the already available dye treatment techniques. So far, numerous research data have been published on the applications of MO NPs in antimicrobial and anticancer applications, photocatalysis, and wastewater treatment. In recent trends, Zinc Oxide nanoparticles (ZnO NPs) have been reported to possess strong photocatalytic properties depending upon the sources of energy, UV irradiation and surface hydroxyl radicals. The biological synthesis route has provided a better, safer, and efficient way of fabricating ZnO NPs for bioremediation purposes. The present study is the first and foremost report on the synthesis of ZnO NPs using Ruellia tuberosa for antimicrobial and bioremediation purposes. The physical and chemical compositions of ZnO NPs analysed using UV–Vis spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray spectroscopy (EDAX), and Transmission electron microscopy (TEM) revealed rod shaped NPs with a size of 40–50 nm. ZnO NPs exhibited higher antibacterial activity against Gram negative bacteria, especially Escherichia coli. Further, textile fabrics were coated with ZnO NPs to prevent the growth of Escherichia coli. In an environmental perspective, ZnO NPs degraded 94% and 92% of methylene blue (MB) and malachite green (MG), respectively. Thus, the present study will give a brief idea on the application of ZnO NPs in the textile industry for the degradation of synthetic dyes and inhibition of pathogenic bacteria. The present study is novel, simple, compatible and hence, can be utilized for future biomedical and environmental applications.

Enhanced photocatalytic degradation of water pollutants using bio-green synthesis of zinc oxide nanoparticles (ZnO NPs)

Sodium alginate (Na-Alg) is water-soluble, neutral, and linear polysaccharide. It is the derivative of alginic acid which comprises 1,4-β-d-mannuronic (M) and α-l-guluronic (G) acids and has the chemical formula (NaC6H7O6). It shows water-soluble, non-toxic, biocompatible, biodegradable, and non-immunogenic properties. It had been used for various biomedical applications, among which the most promising are drug delivery, gene delivery, wound dressing, and wound healing. For different biomedical applications, it is used in different forms with the help of new techniques. That is the reason it had been blended with different polymers. In this review article, we present a comprehensive overview of the combinations of sodium alginate with natural and synthetic polymers and their biomedical applications involving delivery systems. All the scientific/technical issues have been addressed, and we have highlighted the recent advancements.

https://www.mdpi.com/2227-9717/9/1/137/pdf

A Critical Review on the Synthesis of Natural Sodium Alginate Based Composite Materials: An Innovative Biological Polymer for Biomedical Delivery Applications

Herin, we prepared silver NPs using jasmine flower extract. The green synthesis process reports a eco-friendly, nontoxic, cost-effective and simple approach to the synthesis of metal and metal oxide nanoparticles. Extract of jasmine flower acts as capping as well as stabilizing agent. The average crystalline size of the XRD pattern is estimated to be 40 nm. FT-IR (Fourier Transform Infrared) spectra confirm the existence of Ag NPs. The UV-Visible spectrum exhibits an absorption peak of between 380 and 440 nm. Structural analysis for silver nanofibers reveals with SEM and TEM technique. The antimicrobial activity of silver NPs was tested for both grams positive and negative bacteria by Agar well diffusion method. Methylene blue is used as a pollutant dye. Silver nanoparticles result in a maximum degradation efficiency of 78% at the end of 120 min.

Critical green routing synthesis of silver NPs using jasmine flower extract for biological activities and photocatalytical degradation of methylene blue

Green synthesis of nano-silver using Syzygium samarangense flower extract for multifaceted applications in biomedical and photocatalytic degradation of methylene blue

Sony M. Michael Mary

Papers

Critical green routing synthesis of silver NPs using jasmine flower extract for biological activities and photocatalytical degradation of methylene blue

Green synthesis of nano-silver using Syzygium samarangense flower extract for multifaceted applications in biomedical and photocatalytic degradation of methylene blue