Swift Fabrication of Silver Nanoparticles Using Bougainvillea glabra: Potential Against the Japanese Encephalitis Vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae)

Abstract

Mosquitoes are the most critical group of insects in the context of public health, since they transmit key parasites and pathogens, causing millions of deaths annually. Culex tritaeniorhynchus is an important vector of Japanese encephalitis (JE) across urban and semi-urban areas of Asia. In this study, we bio-fabricated silver nanoparticles (Ag NP) using the leaf extract of Bougainvillea glabra as reducing and stabilizing agent. The synthesis of Ag NP was confirmed analyzing the excitation of surface Plasmon resonance using ultraviolet–visible (UV–vis) spectrophotometry. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the clustered and irregular shapes of Ag NP. The presence of silver was determined by energy dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy analysis investigated the identity of secondary metabolites, which may act as Ag NP capping agents. The acute toxicity of B. glabra extract, synthesized Ag NP and a combined treatment testing blends of both mosquitocidals was evaluated against larvae and pupae of Cx. tritaeniorhynchus.B. glabra showed LC50 of 198.93 (larva I), 234.50 (II), 309.18 (III), 371.69 (IV) and 466.09 (pupa) µg/ml, Ag NP LC50 ranged from 7.77 (I) to 19.44 µg/ml (pupa). Combined treatments with B. glabra leaf extract plus 5.12.5 µg/ml of Ag NP lowered the botanical LC50 to 66.09 (I), 76.48 (II), 99.02 (III), 133.43 (IV) and 179.74 µg/ml (IV), respectively. The effectiveness of green-fabricated Ag NP against the JE vector was confirmed in adulticidal tests, as well as evaluating the impact of Ag NP on fecundity and longevity of adult mosquitoes. Lastly, the larvicidal effectiveness of Ag NP was confirmed in the field, treating sewage water bodies. Overall, this study suggests that the green-synthesized Ag NP fabricated using B. glabra can be considered a potential mosquito control device against the JE vector, C. tritaeniorhynchus in Asian regions

Ultra-sonication enhanced green synthesis of silver nanoparticles using Barleria buxifolia leaf extract and its possible application

“…Those peaks are consistent with the JCPDS card No 65-2871of the AgNPs. Also our results strongly agreement with previous reports, that the sharp diffraction peaks with negligible noise verify the high quality of crystallinity that attributed to face-centered cubic (fcc) spinel structure of AgNPs [48,49]. In this manner, the normal grain size of the AgNPs was computed from the solid re ection peak by (111) arrangement utilizing Scherer formula.…”

Evaluation of Pistia stratiotes fractions as effective larvicide against Anopheles mosquitoes

“…Numerous efforts have been made in the past to control its morbidity and mortality [1]. Treatment of the vector at the various developmental stages with insecticides has received wide acceptability, though these synthetic products suffer from major disadvantages of resistance and environmental pollution [2,3]. Plants are rich source of alternative agents for control of mosquitoes, because they possess bioactive chemicals, which act against limited number of species including specific target-insects and are eco-friendly [4].…”

Bio‐inspired synthesis of AgNPs from lichen as potential antibacterial and mosquito larvicidal activity with negligible toxicity on Gambusia affinis

“…Furthermore, Vincent et al . (2017) stated that Bougainvillea glabra extract and green synthesized AgNPs significantly reduced adult longevity in Cx. tritaeniorhynchus .…”