Strong larvicidal potential of silver nanoparticles (AgNPs) synthesized using Holarrhena antidysenterica (L.) Wall. bark extract against malarial vector, Anopheles stephensi Liston

• Published in: Process safety and environmental protection 2018-05, Vol.116, p.137-148
• Main Authors: Kumar, Dinesh, Kumar, Gaurav, Das, Ram, Agrawal, Veena
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetone; Alcohols; Anopheles stephensi; Bark; Biocompatibility; Biosynthesis; Cancer; Chloroform; Disease transmission; Drug delivery; Drug delivery systems; Ethyl acetate; Field emission microscopy; Fourier transforms; Functional groups; Holarrhena antidysenterica; Infrared spectroscopy; Insecticides; Iron; Larvae; Larvicidal activity; Larvicides; Malaria; Methanol; Nanoparticles; Optimization; pH effects; Phenols; Physical properties; Reduction; Scanning electron microscopy; Silver; Silver nanoparticles; Silver nitrate; Spectroscopy; Synthesis; Transmission electron microscopy; X-ray diffraction
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2018.02.001

[Display omitted] •Silver nanoparticles (AgNPs) were synthesized using bark extract of H. antidysenterica.•AgNPs syntheses were characterized by UV–vis, XRD, FE-SEM, FT-IR and TEM.•The most of AgNPs were spherical, hexagonal and triangular in shape with an average size of 40–60nm.•The higher larval mortality was observed in the green synthesized AgNPs with LC50 and LC90 value of 2.672ppm and 4.482ppm, respectively.•GC–MS analysis of bark extract identified 41 compounds having wide range of activities. The present study highlights the strong larvicidal potential of silver nanoparticles (AgNPs) synthesized using bark extract of Holarrhena antidysenterica against third instar larvae of Anopheles stephensi over the other bark extract prepared in chloroform, hexane, ethyl acetate, methanol, aqueous and acetone individually. AgNPs were prepared by mixing of 90ml of silver nitrate (AgNO3) with 10ml of aqueous bark extract of H. antidysenterica. Optimization of various physical parameters such as temperature, pH, time duration and AgNO3 concentrations was done and 1mM of AgNO3, 7.5pH, 50±2°C temp and time 120min proved optimum for best synthesis of AgNPs. Characterized of AgNPs was done by ultraviolet-visible spectroscopy (UV–vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). XRD pattern of such AgNPs revealed characteristics Bragg’s reflection peaks at (38.34) 111, (44.54) 200, (64.36) 220 and (76.9) 311 lattice planes indicating the crystalline nature of biologically synthesized AgNPs. FT-IR analysis of AgNPs exhibited the presence of functional groups of various compounds including phenols, alcohols, amine, amide which were responsible for the reduction and capping of AgNPs. The FE-SEM and TEM images showed that most of the AgNPs were spherical, hexagonal and triangular in shape varying from 40 to 60nm in size. Larvicidal activity of these AgNPs and bark extracts prepared in different solvents such as hexane, ethyl acetate, methanol, water and chloroform were tested separately against the A. stephensi larvae for 24h. Maximum larval mortality was seen with bark extract synthesized AgNPs having LC50 and LC90 value of 2.672ppm and 4.482ppm, respectively compared to chloroform, hexane, ethyl acetate, methanol, water and acetone bark extracts where the LC50 values were 3.0, 31.56, 41.92, 96.40, 121.53 and 1.91E3ppm, respectively. Incidentally