A novel approach for synthesis of silver nanoparticles using Pila virens shell and its mosquito larvicidal activity.

Mosquito act as a vector for variety of deadly diseases. In this study, larvicide activity was investigated in relation to Aedes aegypti (A. aegypti) and Culex quinquefasciatus (C. quinquefasciatus) of synthesised silver nanoparticles (AgNPs) of the Pila virens (P.virens) shell extract. The characterization techniques UV-vis spectral, Fourier transforms infrared spectroscopy (FTIR),High Resonance Scanning electron microscope (HR-SEM) analysis, X-ray diffraction studies (XRD), High Resonance-Transmission electron microscopy (HR-TEM) used to characterize biosynthesized AgNPs. UV-vis, absorption showed peaks of 450 nm for the biosynthesised AgNPs, SEM observed spherical shaped particles of 25.9-28.9 nm in size and the XRD pattern shows the synthesized AgNPs fcc structure. FTIR investigation shown that the esters, carboxylic acid and ether as functional groups have been intricate in the reduction of metal ions. The larvicidal efficacy of synthesized AgNPs towards a larvae of A. aegypti LC50and LC90 value of (37.87 and 132.86 ppm) and C. quinquefasciatus was (14.70 and 28.96 ppm) respectively. The synthesized AgNPs of P. virens confirmed highest mortality towards larvae of and A. aegypti and C. quinquefasciatus.

GC-MS analysis of bioactive components and biosynthesis of silver nanoparticles using Hybanthus enneaspermus at room temperature evaluation of their stability and its larvicidal activity.

Green synthesis of silver nanoparticles (AgNPs) using Hybanthus enneaspermus extract at room temperature that act as a reducing agent as well as capping agent has been investigated. The synthesized AgNPs were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), zeta potential, and dynamic light scattering (DLS) transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX). The silver surface plasmon resonance was observed at 420 nm in the UV-visible spectrum. XRD peaks were observed at 2θ values in 38.20°, 44.40°, 64.60°, and 77.50° which are indexed as (111), (200), (220), and (311) bands of face-centered cubic (fcc) structures of silver. FTIR revealed the AgNPs were capped with plant compounds of alcohol, phenols, carbonyl, amines, and amide functional groups. TEM image shows that the particles were of spherical, hexagonal, and triangular in shape, and the size range was 16-26 nm. Further, DLS exhibits the average size of 25.2 nm and the zeta values were measured (-27.1 mV) which proves the stability of the AgNPs. The conversion of Ag(+) ions into Ag(0) was calculated using inductively coupled plasma atomic emission spectroscopy (ICP-MS) and was found to be 96 %. The biosynthesized AgNPs showed the larvicidal activity with the LC50 values of 17.24 and 13.12 mg/L against the fourth-instar larvae of Anopheles subpictus and Culex quinquefasciatus, respectively. The GC-MS analysis of the plant extract showed that 39 bioactive phytochemical compounds have been found to possess a wide range of activities, which may help in the protection against incurable diseases.

An investigation on cytotoxic effect of bioactive AgNPs synthesized using Cassia fistula flower extract on breast cancer cell MCF-7.

A single step protocol to produce biofunctionalized silver nanoparticles (AgNPs) using the aqueous extract of Cassia fistula flower as "natural factory" was investigated. The reaction between silver ions and aqueous flower extract after the bioreduction process has resulted in the formation of reddish brown color colloidal solution. XRD pattern showed the face centered cubic crystalline structure of AgNPs and exhibited spherical morphology as characterized by FE-SEM. FTIR studies identified different functional groups involved in effective capping of AgNPs. The zeta potential affirmed the phytoreduced AgNPs possess good stability and the size of the particle was measured by DLS. The synthesized AgNPs displayed effective cytotoxic potential against MCF7 and the inhibitory concentration (IC50) was recorded at 7.19 µg/mL. The apoptotic effects of the AgNPs were also confirmed by AO/EB staining. The investigation presents preliminary evidence that biosynthesized AgNPs can be used in the development of novel anticancer drugs.

Evaluation of zinc oxide nanoparticles toxicity on marine algae chlorella vulgaris through flow cytometric, cytotoxicity and oxidative stress analysis.

The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnO NPs) was investigated in Marine algae Chlorella vulgaris (C. vulgaris). High zinc dissociation from ZnONPs, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONPs toxicity. To examine the mechanism of toxicity, C. vulgaris were treated with 50mg/L, 100mg/L, 200mg/L and 300 mg/L ZnO NPs for 24h and 72h. The detailed cytotoxicity assay showed a substantial reduction in the viability dependent on dose and exposure. Further, flow cytometry revealed the significant reduction in C. vulgaris viable cells to higher ZnO NPs. Significant reductions in LDH level were noted for ZnO NPs at 300 mg/L concentration. The activity of antioxidant enzyme superoxide dismutase (SOD) significantly increased in the C. vulgaris exposed to 200mg/L and 300 mg/L ZnO NPs. The content of non-enzymatic antioxidant glutathione (GSH) significantly decreased in the groups with a ZnO NPs concentration of higher than 100mg/L. The level of lipid peroxidation (LPO) was found to increase as the ZnO NPs dose increased. The FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (FESEM and CM).

The Green synthesis of gold nanoparticles using an aqueous root extract of Morinda citrifolia L.

In the present work, we describe the synthesis of gold nanoparticles using an aqueous root extract of Morinda citrifolia. UV-vis spectroscopy, XRD, FTIR, FE-SEM, EDX and TEM were performed to characterize the formation of gold nanoparticles. The synthesized gold nanoparticles were characterized by a peak at 540 nm in the UV-vis spectrum. The XRD peaks at 38°, 44°, 64° and 77° can be indexed to the (111), (200), (220) and (311) Bragg's reflections of cubic structure of metallic gold, respectively. The FTIR result showed that extract containing protein might be responsible for the formation of the nanoparticles and may play an important role in the stabilization of the formed nanoparticles. FESEM images revealed that the particles were triangle and mostly spherical in shape. TEM images clearly revealed the size of the nanoparticles were 12.17-38.26 nm in size.

Biosynthesis, characterization and cytotoxic effect of plant mediated silver nanoparticles using Morinda citrifolia root extract.

Silver has been used since time to control bodily infection, prevent food spoilage and heal wounds by preventing infection. The present study aims at an environmental friendly method of synthesizing silver nanoparticles, from the root of Morinda citrifolia; without involving chemical agents associated with environmental toxicity. The obtained nanoparticles were characterized by UV-vis absorption spectroscopy with an intense surface plasmon resonance band at 413 nm clearly reveals the formation of silver nanoparticles. Fourier transmission infra red spectroscopy (FTIR) showed nanopartilces were capped with plant compounds. Field emission-scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM) showed that the spherical nature of the silver nanoparticles with a size of 30-55 nm. The X-ray diffraction spectrum XRD pattern clearly indicates that the silver nanoparticles formed in the present synthesis were crystalline in nature. In addition these biologically synthesized nanoparticles were also proved to exhibit excellent cytotoxic effect on HeLa cell.