Search

In order to investigate the physicochemical properties and bioactivities of AgNPs prepared using green and chemical approaches and further explore the related antibacterial mechanism, one kind of chemical AgNPs (C-AgNPs) and three kinds of green AgNPs (G-AgNPs) mediated with aqueous extracts of Morus alba L. were prepared and characterized. All G-AgNPs displayed higher antioxidant activities in DPPH radical scavenging, reducing power and total antioxidant assays than C-AgNPs and extracts. Meanwhile, all G-AgNPs exerted significantly (P < 0.05) enhanced antimicrobial activities against various pathogens compared with C-AgNPs and extracts. Among prepared AgNPs, ML-AgNPs mediated with aqueous extract of Morus alba L. leaves exhibited the most powerful antibacterial effect with the largest inhibition zones (13.11 ± 0.76 mm for S. aureus, 13.27 ± 0.22 mm for E. coli) and the lowest minimum inhibition concentrations against S. aureus (6.125 μg/ml) and E. coli (3.125 μg/ml). ML-AgNPs could inhibit the growths of S. aureus and E. coli in time- and dose-dependent modes, and even could disrupt the bacterial structure integrality resulting in the leakage of intracellular contents. G-AgNPs, especially ML-AgNPs, with remarkable bioactivities could replace C-AgNPs as related agents applied in agriculture and medicine. [ABSTRACT FROM AUTHOR]

Mosquito control is facing a challenge worldwide, due to ineffectiveness of chemical insecticides. Identification of novel and ecofriendly insecticides is the need of the hour. In the present study mosquito control efficacy, antioxidants and anti-cancerous potential of silver nanoparticle conjugated with Carmona retusa (Vahl) Masam nanoparticles. Synthesized nanoparticles had UV absorption maximum at 420 nm, size ranging between 20 and 40 nm based of TEM, has cubic structure, C-H bending and Ag Metal bands. Results show high free radical scavenging ability of C. retusa derived silver nanoparticles as evidenced by DPPH radical and H2O2 radical assay. C. retusa derived nanoparticles produce 80% inhibition in MCF-7 cell line at concentration of 500 μg/ml. High larvicidal activity with LC50 values of 116.681 ppm for Anopheles stephensi, 198.766 ppm for Aedes aegypti, and 83.553 ppm for Culex quinquefasciatus were observed. Based on the findings of the study we suggest that C. retusa plant mediated AgNPs has anticancerous and mosquito larvicidal property and could be bioprospected for drug development and mosquito control. [ABSTRACT FROM AUTHOR]

A facile and green route for the synthesis of metallic nanoparticles is of significant intriguing, as it provides simple, rapid, clean, nontoxic, easily available, energy-efficient, cost-effective fabrication method. We reported environmentally benign and unexplored plant Aglaia elaeagnoidea flower extract for the synthesis of spherical and crystalline silver (Ag) and gold (Au) nanoparticles with an excellent robustness against agglomeration. The resultant nanoparticles were characterized using UV-Vis spec., FTIR, XRD, FESEM, EDAX, and TEM techniques. The uniqueness of our method lies in fast synthesis (10 min for Ag NPs) and ultra rapid homogeneous and heterogeneous complete degradation of Methylene Blue and Congo Red within few seconds using the synthesized Ag and Au NPs as the catalyst, respectively. Whereas more than 90% conversion of 4-Nitrophenol to 4-Aminophenol within few minutes for homogenous and few seconds for heterogeneous method using Ag and Au NPs were obtained. Hence, the results of this study demonstrate the possible application of biosynthesized of Ag and Au NPs as nanocatalyst in waste water treatment. [ABSTRACT FROM AUTHOR]