Toxicities of synthesized green iron oxide nanoparticles on Trialeurodes vaporariorum and their effects on antioxidant enzymes and lipid peroxidation

In this study, lethal concentrations of iron-oxide nanoparticles (FeONPs) synthesized from plants (alfalfa, basil, eucalyptus, cinnamon) were investigated for their effects on mortality, antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferases (GST)) and lipid peroxidation (LPO) to develop an effective and inexpensive method for controlling the economic losses caused by Trialeurodes vaporariorum. The characterization of prepared FeONPs with plant extracts was performed using an ultraviolet-visible spectrophotometer (UV-Vis), Fourier transforms infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) to examine the size, elemental composition, and morphology. The UV-Vis results of the green synthesized FeONP showed a peak at 256 nm, confirming the synthesis of FeONPs. An FTIR detected strong absorption peaks at 3420, 3446, 3421, and 3446 cm−1 (hydroxyl group); 2925 and 2926 cm−1 (C–H group); 1618, 1636, 1647, and 1716 cm−1 (C=O group), at approximately 1030, 1034, 1044, and 1048 cm−1 (C–O group). Bioassay tests have been conducted with adults of T. vaporariorum in plastic leaf cages treated with different concentrations of FeONPs. SPSS 21 software (IBM, New York, US) with a confidence interval (CI) of 95% and Probit analysis was employed to determine lethal concentrations (LC10, LC25, LC30, and LC50) of synthesized FeONPs. The results demonstrated that basil, alfalfa, eucalyptus and cinnamon FeONPs effectively killed 50% of T.vaporariorum adults, at concentrations of 4.876, 16.935, 10.584 and 11.948 mg L-1, respectively. Significant increases in LPO, GST, GPX, CAT, and SOD activities were observed in T.vaporariorum adults exposed to the lethal concentrations of different FeONPs. Moreover, the findings suggested that exposure to FeONPs induced oxidative stress in T. vaporariorum adults and may decline their longevity in greenhouses.