It is expected that the number and variety of engineered nanoparticles will increase rapidly over the next few years, and there is a need for new methods to quickly test the potential toxicity of these materials. Because experimental evaluation of the safety of chemicals is expensive and time-consuming, computational methods have been found to be efficient alternatives for predicting the potential toxicity and environmental impact of new nanomaterials before mass production. Here, we show that the quantitative structure-activity relationship (QSAR) method commonly used to predict the physicochemical properties of chemical compounds can be applied to predict the toxicity of various metal oxides. Based on experimental testing, we have developed a model to describe the cytotoxicity of 17 different types of metal oxide nanoparticles to bacteria Escherichia coli. The model reliably predicts the toxicity of all considered compounds, and the methodology is expected to provide guidance for the future design of safe nanomaterials.

The adsorption of Sarin (GB), isopropyl methylphosphonofluoridate (C 4 H 10 FO 2 P), on the surface of magnesium oxide was investigated at the B3LYP/6-31G(d) and MP2/6-31G(d) levels of theory using the representative cluster models. The geometry of Sarin was fully optimized, while the geometry of the oxide fragment was kept frozen. The location and orientation of GB on the surface of MgO were found in cases when Sarin is physadsorbed or chemadsorbed. The adsorption results in the polarization and the electron density redistribution of GB. The interaction energies of Sarin-magnesium oxide corrected by the BSSE energy were predicted. The adsorption energy obtained at the MP2/6-31G(d) level of theory for the most stable chemadsorbed system is about -50 kcal/mol. The adsorption on the small fragment of MgO can lead to decomposition of Sarin.

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The adsorption of sarin (GB), isopropyl methylphosphonofluoridate (C4H10FO2P), and soman (GD), 3,3-dimethyl-2-butyl methylphosphonoflouridate (C7H16FO2P), on the octahedral and tetrahedral surfaces of dickite was investigated using the ONIOM(B3LYP/6-31G(d,p):PM3) and ONIOM(B3LYP/6-31G(d,p):HF/3-21G) methods and the representative cluster models. In the case of adsorption on the octahedral sheet of dickite, the location of six hydrogen atoms of the outer −OH groups and the geometry of the adsorbed molecules were optimized. In the case of adsorption on the tetrahedral side of the dickite layer, the geometry of the mineral fragment was kept frozen. The location and orientation of GB and GD on the tetrahedral and octahedral surfaces of dickite were found. The adsorption on the surface of minerals occurs because of the formation of multiple hydrogen bonds between adsorbed GB and GD and the hydroxyl groups (the octahedral side) and the basal oxygen atoms (the tetrahedral side). This type of adsorption results in the polarization and the electron density redistribution of GB and GD on the surface of the mineral. The interaction energies of sarin and soman with the octahedral and tetrahedral surfaces corrected by the BSSE energy were found. The adsorption energies obtained at the ONIOM(B3LYP/6-31G(d,p):PM3) level of theory and using large models of the mineral for the adsorption systems of GB and GD on the octahedral surface of dickite are about −16 and −15 kcal/mol, respectively. In the case of adsorption on the tetrahedral surface, the interaction energies of adsorption systems with GB and GD are about −7.0 and −9.0 kcal/mol, respectively.