Green Synthesis of Silver Nanoparticles by Using Neem (Azadirachta Indica) and Amla (Phyllanthus Emblica) Leaf Extract

Antibacterial and Dye Degradation Activity of Green Synthesized Iron Nanoparticles

Nanoparticles have a wide range of applications in various fields such as cosmetics, pharmaceuticals, and agrochemicals. Synthesis of nanoparticles using plant extract is a very efficient, cost-effective, useful, and environmentally friendly method. A plant extract acts as a reducing agent in the formation of nanoparticles. Catharanthus roseus is one of the potential plants for biosynthesis of nanoparticles due to its easy availability. In the present study, the Catharanthus roseus plant extract was used to synthesize iron nanoparticles. UV-vis spectroscopy, DLS, and FTIR were performed for characterization of synthesized nanoparticles. Further antibacterial and dye degrading properties of synthesized iron nanoparticles have been investigated. It was found that Catharanthus roseus-synthesized iron nanoparticles showed antibacterial activity against E. coli and dye degradation activity against methyl orange dye.

Synthesis and characterisation of neem leaf extract, 2, 3-dehydrosalanol and quercetin dihydrate mediated silver nano particles for therapeutic applications

The utility of green silver nanoparticles (AgNPs) in veterinary medicine is steadily increasing as they have many therapeutic applications against pathogens and arthropods of livestock. In this study, green AgNPs using neem (N-AgNPs), 2,3-dehydrosalanol (2,3-DHS-AgNPs) and quercetin dihydrate (QDH-AgNPs) were synthesised and characterised. Synthesised compounds were characterised by UV-Vis spectroscopy and the peak absorbance was recorded at 370 nm for neem extract. For N-AgNPs, 2,3-DHS-AgNPs and QDH-AgNPs, the maximum absorbance peaks were at 430, 230 and 220 nm, respectively. The FTIR analysis confirmed the synthesis of green AgNPs. The XRD pattern of N-AgNPs showed the peaks corresponding to whole spectra of 2 θ values ranging from 10-80. The relatively higher intensity of (111, 222) planes in face centred cubic crystalline structure supports the formation of synthesised AgNPs. In DLS analysis, the hydrodynamic diameter of neem leaf extract was found to be 259.8 nm, followed by 5.3, 6.7 and 261.8 nm for 2,3-DHS-AgNPs, N-AgNPs and QDH-AgNPs, respectively. Based on the transmission electron microscopy and scanning electron microscopy image analyses, confirmed the formation of N-AgNPs, 2,3-DHS-AgNPs and QDH-AgNPs. These eco-friendly phyto-AgNPs may be of use as an effective alternative to chemical control methods against the arthropods of livestock.

Temperature Dependent Electrical Properties of Green Synthesized Silver Nanoparticles-Polyaniline Composite

Polyaniline (PANI) Nanocomposites are potential materials for actuators, EMI shielding, Fuel cells and components in non volatile memory. Silver nanoparticles have wide range of applications such as catalysis, microelectronics, biotechnology and silver-oxide batteries. This work reports the effect of thermal alteration [lowhigh temperatur on the electrical conductivity of green synthesized silver (Ag) nanoparticles-polyaniline composite. A simple low cost green synthesis using Azadirachta indica [Neem] extract is employed for synthesis of silver nanoparticles; Polyaniline is prepared by redox polymerization of aniline using ammonium per sulphate. The silver nanoparticles are incorporated into Polyaniline during polymerization. PANI and PANI-Ag composites are characterized by FTIR, UV-Vis, TGA, XRD, TEM and DC conductivity. The DC conductivity and UV-Vis spectral response were recorded for the samples at low temperatures [263K, 273K, and 283 and high temperatures [353K, 433K, and 533. The effect of thermal alteration showed a significant change in both conductivity and UV-Vis spectral response. UV-visible spectra show the transition occurring in PANI Emeraldine salt phase to Pernigraniline with increase in temperature. TGA analysis confirms the improved thermal stability for PANI-Ag composite. The mechanism of electrical conductivity with temperature in the system is investigated and reported. Thus, this work deals with an approach to analyze the electrical behavior of green synthesized silver nanoparticles composited with a conducting polymer. The results show that these composites can be suitable for temperature dependent semiconductors, bio sensors and catalytic reactions.