title: Facile fabrication of eco-friendly nano-mosquitocides: Biophysical characterization and effectiveness on neglected tropical mosquito vectors.
abstract: Mosquito (Diptera: Culicidae) vectors are solely responsible for transmitting important diseases such as malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and Zika virus. Eco-friendly control tools of Culicidae vectors are a priority. In this study, we proposed a facile fabrication process of poly-disperse and stable silver nanoparticles (Ag NPs) using a cheap leaf extract of Ichnocarpus frutescens (Apocyanaceae). Bio-reduced Ag NPs were characterized by UV-vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The acute toxicity of I. frutescens leaf extract and green-synthesized Ag NPs was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Compared to the leaf aqueous extract, Ag NPs showed higher toxicity against A. subpictus, A. albopictus, and C. tritaeniorhynchus with LC50values of 14.22, 15.84 and 17.26μg/mL, respectively. Ag NPs were found safer to non-target mosquito predators Anisops bouvieri, Diplonychus indicus and Gambusia affinis, with LC50values ranging from 636.61 to 2098.61μg/mL. Overall, this research firstly shed light on the mosquitocidal potential of I. frutescens, a potential bio-resource for rapid, cheap and effective synthesis of poly-disperse and highly stable silver nanocrystals.
authors.affiliation: Unit of Vector Control, Phytochemistry and Nanotechnology, Department of Zoology, Annamalai University, Annamalainagar, 608 002 Tamil Nadu, India. Electronic address: drgovind1979@gmail.com.
authors.forename: Marimuthu
authors.initials: M
authors.lastname: Govindarajan
authors.affiliation: Regional Medical Research Centre, Nehru Nagar, Belgaum 590010, Karnataka, India.
authors.forename: S L
authors.initials: SL
authors.lastname: Hoti
authors.affiliation: Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy. Electronic address: g.benelli@sssup.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
mesh_terms: D000818:Animals; D029062:Apocynaceae / Q000378:metabolism; D055592:Biophysical Phenomena; D001709:Biotechnology; D055772:Green Chemistry Technology; D006801:Humans; D007306:Insecticides / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D007814:Larva / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D000072138:Mosquito Vectors / Q000187:drug effects* / Q000469:parasitology / Q000821:virology; D036103:Nanotechnology; D010936:Plant Extracts / Q000378:metabolism; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D007306:Insecticides; D010936:Plant Extracts; D012834:Silver
keywords: Aedes albopictus; Anopheles subpictus; Culex tritaeniorhynchus; Green synthesis; Nanotechnology; Plant-borne larvicides