Novel developments of ZnO/SiO2 nanocomposite: a nanotechnological approach towards insect vector control

Recently, there is increasing efforts to develop newer and effective larvicides to control mosquito vectors. This study was carried out to examine the efficacy of ZnO/SiO2 nanocomposite synthesized using Gum Arabic against Culex quinquefasciatus larvae. The elemental composition, morphology, functional groups and surface plasmon resonance of the ZnO@SiO2 nanocomposite was analyzed by Energy dispersive X-ray analysis (EDX), Scanning electron microscope (SEM), FTIR and UV-Visible spectroscopy respectively. In bioassay, larvae were exposed to three different concentrations of synthesized ZnO/SiO2 nanocomposite. The mortality rates at concentrations of 10, 20 and 25 were found to be (70%, 80%, 86%), (56%, 64%, 84%) and (44%, 48%, 76%) for 1st, 2nd, and 3rd instar respectively. This study revealed that the synthesized ZnO@SiO2 nanocomposite exhibit high larvicidal activity; 1st instar (LC50=4.024, LC90= 39.273 mg/l), 2nd instar (LC50=8.767, LC90=51.069 mg/l) and 3rd instar (LC50=13.761.LC90=81.809 mg/l).