Avaliação dos Pontos Quânticos de Óxido de Zinco (PQs ZnO) na mortalidade de imaturos de Aedes aegypti (Diptera: Culicidae)

Abstract

The specie Aedes aegypti is the greatest medical importance in Brazil, can transmit the dengue virus, urban yellow fever, zika, chinkungunya and others arboviruses. Insecticides still appear as an important tool in mosquito control programs, but the strategy is threatened by the development of populations resistant to organophosphates and pyrethroids. Science seeks new techniques to address this cause, such as obtaining and manipulating materials from nanotechnology, which has been widely diffused due to properties and characteristics that do not exist in any other product at higher scales. In recent years, zinc oxide quantum dots (ZnO QDs) have received a lot of attention, playing an important role in various technological domains such as drug delivery, bioimaging, sensor for chemical and biological detection, they have a high bactericidal and virucidal action, and optimize cancer diagnoses. The objective of this research was to verify the use of ZnO QDs in the mortality of immature Aedes aegypti. The morphological and structural properties were characterized by Dynamic Light Scattering (DLS), Field Scanning Electron Microscopy High Resolution (MEV / FEG), X - ray Diffraction (XRD) and Transmission Electron Microscopy (MET). In the bioassay performed with A. aegypti larvae under different concentrations of ZnO QDs, concentrations 7 and 14 mg/mL had 15% and 60% mortality on larvae, respectively, while 22 and 29 mg/mL reached 100% of larvae. mortality. With DL50 and DL90, respectively, 12.3 mg/mL and 17 mg/mL. In another bioassay, with 14 and 29 mg/mL, it was observed that in both absence and presence of ultraviolet light (UV) there was mortality, highlighting 29 mg/mL with 100% mortality on larvae, indicating that the presence of UV light influence (p <0.01) on larval mortality. ZnO QDs has been shown to be effective in mosquito control at concentrations above 3 mg/mL, however, further testing is required to understand its action on A. aegypti larvae.