Achillea millefolium L. extract mediated green synthesis of waste peach kernel shell supported silver nanoparticles: Application of the nanoparticles for catalytic reduction of a variety of dyes in water

2017 ◽  
Vol 493 ◽  
pp. 85-93 ◽  
Author(s):  
Bahar Khodadadi ◽  
Maryam Bordbar ◽  
Mahmoud Nasrollahzadeh
2019 ◽  
Vol 31 (11) ◽  
pp. 2439-2442
Author(s):  
Karuppiah Muthu ◽  
B. Akilandaeaswari ◽  
S. Mangala Nagasundari

In this present study, green synthesis of silver nanoparticles (AgNPs) was synthesized from silver nitrate using the reducing agents of Polyalthia longifolia bark extract and applied the catalyst in the reduction/degradation of environmental polluted organic compound in the presence of NaBH4. Initially, the colourless reaction mixture was slowly changed to yellowish brown, UV-visible spectroscopy of surface plasmon resonance centre at 447 nm confirmed the formation of AgNPs. High resolution transmission electron microscopy (HRTEM) clearly identified the spherical shapes nanoparticles with diameters sizes 5-25 nm. This AgNPs has excellent catalyst in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as compared to the reducing agent of NaBH4 (chemical) and plant extract (natural).


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1999
Author(s):  
Kaushik Kumar Bharadwaj ◽  
Bijuli Rabha ◽  
Siddhartha Pati ◽  
Bhabesh Kumar Choudhury ◽  
Tanmay Sarkar ◽  
...  

The green synthesis of silver nanoparticles (AgNPs) has currently been gaining wide applications in the medical field of nanomedicine. Green synthesis is one of the most effective procedures for the production of AgNPs. The Diospyros malabarica tree grown throughout India has been reported to have antioxidant and various therapeutic applications. In the context of this, we have investigated the fruit of Diospyros malabarica for the potential of forming AgNPs and analyzed its antibacterial and anticancer activity. We have developed a rapid, single-step, cost-effective and eco-friendly method for the synthesis of AgNPs using Diospyros malabarica aqueous fruit extract at room temperature. The AgNPs began to form just after the reaction was initiated. The formation and characterization of AgNPs were confirmed by UV-Vis spectrophotometry, XRD, FTIR, DLS, Zeta potential, FESEM, EDX, TEM and photoluminescence (PL) methods. The average size of AgNPs, in accordance with TEM results, was found to be 17.4 nm. The antibacterial activity of the silver nanoparticles against pathogenic microorganism strains of Staphylococcus aureus and Escherichia coli was confirmed by the well diffusion method and was found to inhibit the growth of the bacteria with an average zone of inhibition size of (8.4 ± 0.3 mm and 12.1 ± 0.5 mm) and (6.1 ± 0.7 mm and 13.1 ± 0.5 mm) at 500 and 1000 µg/mL concentrations of AgNPs, respectively. The anticancer effect of the AgNPs was confirmed by MTT assay using the U87-MG (human primary glioblastoma) cell line. The IC50 value was found to be 58.63 ± 5.74 μg/mL. The results showed that green synthesized AgNPs exhibited significant antimicrobial and anticancer potency. In addition, nitrophenols, which are regarded as priority pollutants by the United States Environmental Protection Agency (USEPA), can also be catalytically reduced to less toxic aminophenols by utilizing synthesized AgNPs. As a model reaction, AgNPs are employed as a catalyst in the reduction of 4-nitrophenol to 4-aminophenol, which is an intermediate for numerous analgesics and antipyretic drugs. Thus, the study is expected to help immensely in the pharmaceutical industries in developing antimicrobial drugs and/or as an anticancer drug, as well as in the cosmetic and food industries.


2020 ◽  
Vol 21 (3) ◽  
pp. 206-218 ◽  
Author(s):  
Sadia Nazer ◽  
Saiqa Andleeb ◽  
Shaukat Ali ◽  
Nazia Gulzar ◽  
Tariq Iqbal ◽  
...  

Background: Multi-drug resistance in bacterial pathogens is a major concern of today. Green synthesis technology is being used to cure infectious diseases. Objectives: The aim of the current research was to analyze the antibacterial, antioxidant, and phytochemical screening of green synthesized silver nanoparticles using Ajuga bracteosa. Methods: Extract of A. bracteosa was prepared by maceration technique. Silver nanoparticles were synthesized using A. bracteosa extract and were confirmed by UV-Vis spectrophotometer, Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The antibacterial, anti-biofilm, cell proliferation inhibition, TLC-Bioautography, TLC-Spot screening, antioxidant, and phytochemical screening were also investigated. Results: UV-Vis spectrum and Scanning electron microscopy confirmed the synthesis of green nanoparticles at 400 nm with tube-like structures. FTIR spectrum showed that functional groups of nanoparticles have a role in capping and stability of AgNP. Agar well diffusion assay represented the maximum antibacterial effect of ABAgNPs against Escherichia coli, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, and Pseudomonas aeruginosa at 0.10 g/mL concentration compared to ABaqu. Two types of interactions among nanoparticles, aqueous extract, and antibiotics (Synergistic and additive) were recorded against tested pathogens. Crystal violet, MTT, TLC-bio-autography, and spot screening supported the findings of the antibacterial assay. Highest antioxidant potential effect in ABaqu was 14.62% (DPPH) and 13.64% (ABTS) while 4.85% (DPPH) and 4.86% (ABTS) was recorded in ABAgNPs. Presence of phytochemical constituents showed pharmacological importance. Conclusion: It was concluded that green synthesis is an innovative technology in which natural products are conjugated with metallic particles and are used against infectious pathogens. The current research showed the significant use of green nanoparticles against etiological agents.


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