Sonication and heat-mediated synthesis, characterization and larvicidal activity of sericin-based silver nanoparticles against dengue vector (Aedes aegypti)

Microsc Res Tech. 2023 Oct;86(10):1363-1377. doi: 10.1002/jemt.24333. Epub 2023 Apr 29.

Abstract

Fabrication, characterization and evaluation of the larvicidal potential of novel silk protein (sericin)-based silver nanoparticles (Se-AgNPs) were the prime motives of the designed study. Furthermore, investigation of the sericin as natural reducing or stabilizing agent was another objective behind this study. Se-AgNPs were synthesized using sonication and heat. Fabricated Se-AgNPs were characterized using particle size analyzer, UV spectrophotometry, FTIR and SEM which confirmed the fabrication of the Se-AgNPs. Size of sonication-mediated Se-AgNPs was smaller (7.49 nm) than heat-assisted Se-AgNPs (53.6 nm). Being smallest in size, sonication-assisted Se-AgNPs revealed the significantly highest (F4,10 = 39.20, p = .00) larvicidal activity against fourth instar lab and field larvae (F4,10 = 1864, p = .00) of dengue vector (Aedes aegypti) followed by heat-assisted Se-AgNPs and positive control (temephos). Non-significant larvicidal activity was showed by silver (without sericin) which made the temperature stability of silver, debatable. Furthermore, findings of biochemical assays (glutathione-S transferase, esterase, and acetylcholinesterase) showed the levels of resistance in field strain larvae. Aforementioned findings of the study suggests the sonication as the best method for synthesis of Se-AgNPs while the larvicidal activity is inversely proportional to the size of Se-AgNPs, i.e., smallest the size, highest the larvicidal activity. Conclusively, status of the sericin as a natural reducing/stabilizing agent has been endorsed by the findings of this study. RESEARCH HIGHLIGHTS: Incorporation of biocompatible and inexpensive sericin as a capping/reducing agent for synthesis of Se-AgNPs. A novel sonication method was used for the fabrication of Se-AgNPs which were thoroughly characterized by particle size analyzer, UV-visible spectrophotometry, SEM and FTIR. Analysis of enzymatic (GSTs, ESTs) levels in field and lab strains of Aedes aegypti larvae for evaluation of insecticides resistance.

Keywords: acetycholine; biochemical; dengue; larvicidal; reducing; sonication.

MeSH terms

  • Acetylcholinesterase / analysis
  • Acetylcholinesterase / metabolism
  • Aedes*
  • Animals
  • Dengue* / metabolism
  • Dengue* / prevention & control
  • Excipients / analysis
  • Excipients / metabolism
  • Hot Temperature
  • Insecticides*
  • Larva
  • Metal Nanoparticles* / chemistry
  • Mosquito Vectors
  • Plant Extracts / chemistry
  • Plant Leaves / chemistry
  • Sericins* / pharmacology
  • Silver / chemistry
  • Silver / pharmacology
  • Sonication

Substances

  • Silver
  • Sericins
  • Acetylcholinesterase
  • Excipients
  • Insecticides
  • Plant Extracts