Comparative study on larvicidal activity of green synthesized silver nanoparticles and Annona glabra (Annonaceae) aqueous extract to control Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

L D Amarasinghe; P A S R Wickramarachchi; A A A U Aberathna; W S Sithara; C R De Silva

doi:10.1016/j.heliyon.2020.e04322

Comparative study on larvicidal activity of green synthesized silver nanoparticles and Annona glabra (Annonaceae) aqueous extract to control Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

Heliyon. 2020 Jun 27;6(6):e04322. doi: 10.1016/j.heliyon.2020.e04322. eCollection 2020 Jun.

Authors

L D Amarasinghe¹, P A S R Wickramarachchi², A A A U Aberathna¹, W S Sithara², C R De Silva³

Affiliations

¹ Department of Zoology & Environmental Management, Faculty of Science, University of Kelaniya, Dalugama, GQ 11600, Sri Lanka.
² Department of Chemistry, Faculty of Science, University of Kelaniya, Dalugama GQ 11600, Sri Lanka.
³ Department of Chemistry & Physics, 213 Natural Sciences Building, Western Carolina University, USA.

Abstract

The present study reports mosquito larvicidal potential of green synthesized silver nanoparticles by using Annona glabra leaves (An-AgNPs). Synthesized An-AgNPs were characterized by Ultraviolet-Visible spectroscopy (UV-VIS), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS) technique and Fourier transform infrared spectroscopy (FTIR). Colur change from pale yellow to brick red of the plant extract and AgNO₃ solution indicated the formation of An-AgNPs initially. Surface Plasmon Resonance (SPR) band at 435 nm in the UV-Vis confirmed the formation of An-AgNPs. SEM images showed that An-AgNPs were spherical in shape. FTIR proved that An-AgNPs were functionalized with biomolecules in A. glabra leaves. Based on DLS analysis the average size range of synthesized An-AgNPs was determine to be 10-100 nm and 100-1000 nm. Third instar larvae of dengue vector mosquitoes, Aedes aegypti and Aedes albopictus were subjected to larvicidal bioassays in a range of concentrations of An-AgNPs and A. glabra crude aqueous leaf extract (2-10 mg/L). An-AgNPs exhibited very high larvicidal activity against dengue vector mosquito larvae; LC₅₀ value for Ae. aegypti at 24 h exposure to An-AgNPs (Plant extract: AgNO₃ 1 : 10) 5.29 mg/L; An-AgNPs (Plant extract: AgNO₃ 2 : 10) 2.43 mg/L while LC₅₀ value for Ae. albopictus at 24 h exposure to An-AgNPs (Plant extract: AgNO₃1:10) 3.02 mg/L; An-AgNPs (Plant extract: AgNO₃ 2:10) 2.51 mg/L. LC₅₀ values obtained for A. glabra leaf extract tested against Ae. aegypti and Ae. albopictus are 5.94 mg/L and 5.00 mg/L respectively at 24-hour exposure. This study further revealed that Ae. albopictus is more susceptible than to Ae. aegypti to a given concentration of An-AgNPs and to crude aqueous leaf extract of A. glabra. Larvicidal effect of An-AgNPs is superior to the crude aqueous leaf extract of A. glabra. An-AgNPs is a potent larvicide for dengue vector control.

Keywords: Aedes aegypti; Aedes albopictus; Annona glabra; Chemistry; Environmental science; Green synthesis; Larvicidal activity; Silver nanoparticle.