Surface Plasmon Resonance Based Applications of Silver Nanoflowers Synthesized from Bregnia-Vitis-Idaea Leaves Extract

An environmentally friendly, green synthesis process has opted to synthesize silver nanoparticles (AgNPs) in an aqueous solution from a new remedial plant, Bregnia-Vitis-Idaea leaves act like natural capping and reducing...

Synthesis of Environmentally Friendly Silver Nanoparticles

The nanoparticles synthesized by plants and micro-organisms are environmentally safe and do not leave residues or long-term toxic effects in ecosystems or accumulate in the environment and transfer through the food chain. Therefore, the aim of the research is to synthesize silver nanoparticles from the leaves of the oleander plant, where they are environmentally friendly when used for various purposes such as controlling agricultural pests. The results showed that the leaves of this plant have the ability to synthesize silver nanoparticles and this is confirmed by the tests of color change of the plant extract the reaction solution, the color of the solution changed from colorless to pink. Physical diagnostic tests such as absorption using a UV-Visible spectrophotometer at a wavelength of 340 nm, transmission electron microscope (TEM) and X-ray diffraction (XRD) technique have confirmed the formation of AgNPs in the leaves of a plant oleander. Keywords: silver nanoparticles, synthesis, environmentally friendly, physical diagnosis

Entomopathogenic Fungi Biomass Production and Extracellular Biosynthesis of Silver Nanoparticles for Bioinsecticide Action

Entomopathogenic fungi are microbial agents of insect control in nature. They have been used as biologic strategies to manage insect invasion; however, the challenge is to maintain their shelf life and viability when exposed to high temperatures, ultraviolet radiation, and humidity. Synthesized silver nanoparticles (AgNPs) from fungal extracellular enzymes are an alternative using these microorganisms to obtain nanoparticles with insecticidal action. The present study evaluates the biomass production and the potential to synthesize silver nanoparticles using entomopathogenic fungi isolates. Sixteen isolates of entomopathogenic fungi were used in this study. The fungi pathogenicity and virulence were evaluated using the insect model Tenebrio molitor, at a concentration of 5 × 106 conidia/mL. The fungal biomass was produced in a liquid medium, dried, and weighed. The synthesis of silver nanoparticles was performed with aqueous extracts of the entomopathogenic fungi and silver nitrate solution (1 mM), following characterization by a UV/vis spectrophotometer, mean size, and polydispersity index. The results showed a significant variation in pathogenicity, virulence, and biomass production among the evaluated fungi isolates; however, only one of the isolates did not have the potential to synthesize silver nanoparticles. Pearson’s correlation showed significant correlation values only between virulence × biosynthesis potential and biomass production × biosynthesis potential, both with negative values, indicating an inverse correlation. Thus, AgNPs with entomopathogenic fungus extract can produce an innovative bioinsecticide product using a green production process.

Sintesis dan karakterisai kitosan dari limbah cangkang udang sebagai stabilizer terhadap Ag nanopartikel

The research of manufacturing chitosan from shrimp shell waste , and their use as a stabilizer in the manufacture of silver nanoparticles has been done. The aim of the research was to synthesize silver nanoparticles using chitosan as a stabilizer by chemical reduction method and determine the effect of chitosan concentration on the stability of Ag nanoparticles. In this study, the raw material used is shrimp shell powder and then processed in several stages, eliminating proteins, demineralization, and deacetylation. Chitosan obtained is 16.4 % of shrimp shell powder, with a degree of deacetylation of 85 %. Chitosan is used to synthesize silver nanoparticles as a reducing agent of silver ions in silver nitrate solution and is expected to be stabilizer. Sample containing 45 mg of chitosan and 1000 ppm AgNO3 has 421,60 nm of maximum wavelength, and the average particle size is 154.07 nm.

The Use of Salacca Zalacca Extract as Reducing Agent to Synthesize Silver Nanoparticles (Agnps) and the Antibacterial Activities.

In general, leaf, flower, and fruit of plants contain organic compounds which may reduce metal salts to nanosize metals, or nanoparticles (NPs). The extract of snake fruit (Salacca zallaca) has been used to synthesize silver nanoparticles (AgNPs) using green-one pot method. Some reaction variables ie. incubation time, Salacca zallacca extract concentration, and pH of the mixture of AgNO3 and the extract have been set-up and controlled. The AgNPs were characterized using UV-Vis, FTIR, XRD, and TEM methods. Testing the antibacterial activity of AgNPs was undertaken using the disk diffusion method by measuring the inhibition zones of Staphylococcus aureus and Salmonella typhi bacteria.The AgNPs can be prepared by reducing Ag+ using Salacca zalacca extract as reducing agent. The formation of AgNPs are affected by the incubation time, extract concentration, and pH of the solution. The AgNPs indicate SPR peak absorption at 400-530 nm, and centered cubic (fcc) structures with a particle size of 10 nm. The AgNPs show antibacterial activity against Staphylococcus aureus and Salmonella typhi bacteria.