In this study, Curcubita maxima leaves are used as a novel source for green synthesis of reduced graphene oxide — silver nanoparticle composite in a single pot. Characterization of the novel phyto source–driven composite was performed by UV–visible spectroscopy, Fourier transform infrared analysis, X-ray diffraction analysis, and field emission scanning electron microscopic methods. The assessment of degradation effect of chlorpyrifos by the synthesized nanocomposite was performed. The photocatalytic activity of the composite was demonstrated through two different processes as adsorption under room temperature and photocatalysis in the presence of sunlight. Different parameters such as pH, time, photocatalyst dose and pesticide concentration were optimized. The adsorption isotherms governing the photocatalytic adsorption process were investigated to predict the adsorption capacity of the synthesized nanocomposite. In addition, the results of antimicrobial activity of the nanocomposite against gram-positive, gram-negative bacteria and antifungal activity were also been found to be highly promising to utilize this composite for the removal of microbial contaminations in wastewater treatment. 

/pdf/green-synthesis-of-rgo-agnp-composite-using-curcubita-maxima-2nb362rm.pdf

Green synthesis of rGO-AgNP composite using Curcubita maxima extract for enhanced photocatalytic degradation of the organophosphate pesticide chlorpyrifos

Amine modified nano-silica was prepared via a one-pot route and under very mild conditions in water in oil microemulsion with a non-ionic surfactant to study the effect of changing the amount of N-[3-(Trimethoxysilyl)propyl]ethylenediamine (DA) added to the synthesis mixture on the characteristics of the obtained nanocomposite such as morphology, crystallinity, surface charge, particle size, surface area, and accordingly the effect of all of these factors on the efficiency of the nanocomposite for the removal of heavy metal ions, namely zinc, from aqueous solutions. XRD, SEM, TGA, BET, DLS, FTIR, and pH0 analysis were performed for samples and the results showed a strong effect for the amount of DA added to the synthesis mixture on the characteristics of the obtained nanocomposites. It was found that increasing the amount of DA added to the synthesis mixture increased the pH0, hydrodynamic particle size obtained by dynamic light scattering analysis, and the particle size obtained by SEM. Sample prepared without the addition of DA (SNP) and the samples prepared with 1.5 mL of DA (SNP-1.5DA) showed a better adsorption performance compared to the samples prepared with 0.5 and 1.0 mL of DA (SNP-0.5DA and SNP-1.0DA, respectively). The main factor affecting the adsorption efficiency was found to be the available surface area for each nanocomposite, which was directly related to the degree of crystallinity as obtained by XRD analysis.

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One-Pot Synthesis of Amine-Functionalized Nano-Silica via Sol-Gel Assisted by Reverse Micelle Microemulsion for Environmental Application

The progressive research into the nanoscale level upgrades the higher end modernized evolution with every field of science, engineering, and technology. Silver nanoparticles and their broader range of application from nanoelectronics to nano-drug delivery systems drive the futuristic direction of nanoengineering and technology in contemporary days. In this review, the green synthesis of silver nanoparticles is the cornerstone of interest over physical and chemical methods owing to its remarkable biocompatibility and idiosyncratic property engineering. The abundant primary and secondary plant metabolites collectively as multifarious phytochemicals which are more peculiar in the composition from root hair to aerial apex through various interspecies and intraspecies, capable of reduction, and capping with the synthesis of silver nanoparticles. Furthermore, the process by which intracellular, extracellular biological macromolecules of the microbiota reduce with the synthesis of silver nanoparticles from the precursor molecule is also discussed. Viruses are one of the predominant infectious agents that gets faster resistance to the antiviral therapies of traditional generations of medicine. We discuss the various stages of virus targeting of cells and viral target through drugs. Antiviral potential of silver nanoparticles against different classes and families of the past and their considerable candidate for up-to-the-minute need of complete addressing of the fulminant and opportunistic global pandemic of this millennium SARS-CoV2, illustrated through recent silver-based formulations under development and approval for countering the pandemic situation. 

/pdf/multifarious-global-flora-fabricated-phytosynthesis-of-3jljlfuw.pdf

Multifarious global flora fabricated phytosynthesis of silver nanoparticles: a green nanoweapon for antiviral approach including SARS-CoV-2

Cancer and COVID-19 have been deemed as world health concerns due to the millions of lives that they have claimed over the years. Extensive efforts have been made to develop sophisticated, site-specific, and safe strategies that can effectively diagnose, prevent, manage, and treat these diseases. These strategies involve the implementation of metal nanoparticles and metal oxides such as gold, silver, iron oxide, titanium oxide, zinc oxide, and copper oxide, formulated through nanotechnology as alternative anticancer or antiviral therapeutics or drug delivery systems. This review provides a perspective on metal nanoparticles and their potential application in cancer and COVID-19 treatments. The data of published studies were critically analysed to expose the potential therapeutic relevance of green synthesized metal nanoparticles in cancer and COVID-19. Although various research reports highlight the great potential of metal and metal oxide nanoparticles as alternative nanotherapeutics, issues of nanotoxicity, complex methods of preparation, biodegradability, and clearance are lingering challenges for the successful clinical application of the NPs. Thus, future innovations include fabricating metal nanoparticles with eco-friendly materials, tailor making them with optimal therapeutics for specific disease targeting, and in vitro and in vivo evaluation of safety, therapeutic efficiency, pharmacokinetics, and biodistribution.

/pdf/current-trends-and-prospects-for-application-of-green-5zquvtyj.pdf

Current Trends and Prospects for Application of Green Synthesized Metal Nanoparticles in Cancer and COVID-19 Therapies

With increasing population and growing demands for ‘ready-to-consume’ high-quality fresh produce with longer shelf life, development of smart and intelligent food packaging systems has garnered extensive attention. Chitosan is a linear polysaccharide obtained from chitin, the second most abundant natural biopolymer on earth. Chitosan nanoparticles possess excellent physico-chemical, antimicrobial properties and are versatile due to their surface functionality. Though well-established research on chitosan nanocoatings in aquaculture, meat and meat products are in process, the use of nanochitosan edible formulations—films and coatings with the incorporation of essential oils and extracts for the shelf life extension of fruits remain largely unexplored. This review aims to highlight the significance of nanochitosan and its edible films and coating formulations with a particular focus on edible coatings of nanochitosan supplemented with essential oils and plant extracts to encourage more research work to further explore and develop better coatings for the shelf life extension of fresh produce.

Nanochitosan augmented with essential oils and extracts as an edible antimicrobial coating for the shelf life extension of fresh produce: a review

Nanocomposites have been acknowledged to revolutionize various fields including food science due to their nature-friendly approach, and has gained high-priority in food preservation and safety. In this study, silver nanoparticles (AgNPs) were synthesized using Hydrilla verticillata leaf extract as the reducing agent and nanosilica was prepared from rice husk ash by a simple non-conventional method. The obtained nanosilica was found to be spherical, homogenous, and monodispersed with a diameter range of 11–13.6 nm. The synthesized nanosilica was mixed with reduced silver nanoparticle solution to form silver-silica (Ag–SiO2) nanocomposite. Scanning electron microscopy obervations showed that the nanocomposite was spherical shape with diameter ranges between 20.1–42.6 nm, and the micrograph also revealed that the AgNPs appear as bright spots over the surface of nanosilica. Fourier Transform Infrared Spectroscopy results illustrated the formation of Ag–SiO2 nanocomposite by the changes in intensity and appearance of newer absorption prominent bands compared to nanosilica alone. The X-Ray Diffraction of nanocomposite showed three distinct diffraction peaks recorded at 2θ values 27.84o, 32.28o and 46.25° corresponds and confirms the presence of AgNP in Ag–SiO2. The nanocomposite was then formulated with sodium alginate to form a sodium alginate-based nanocomposite edible coating solution. The effect of the application of the nanocomposite formulation on the quality of fresh apple and pear cut-fruits was evaluated for degree of browning, weight loss, total soluble protein, total phenol content, and microbial growth. The results indicated that the formulation is effective and promising for the preservation of fresh-cut fruits.

D. G. Caroline

Papers

Synthesis, Characterization of Ag-SiO2 Nanocomposite and Its Application in Food Packaging

Multifarious global flora fabricated phytosynthesis of silver nanoparticles: a green nanoweapon for antiviral approach including SARS-CoV-2

Nanochitosan augmented with essential oils and extracts as an edible antimicrobial coating for the shelf life extension of fresh produce: a review