Modeling of Mg₁₂O₁₁-X (X = B, N, P and S) Nanostructured Materials as Sensors for Melamine (C₃H₆N₆)

This research is focused on the sensor properties of pure and X-decorated (X=B, N, P and S) magnesium oxide (Mg12O12) nanocages for melamine (C3H6N6) molecule detection using density functional theory (DFT) electronic structure approach. Comparative adsorption study was carried out on four distinct computational models of hybrid functionals: ωB97XD, PBE0-D3BJ, M062X-D3BJ and DSDPBEP86 with the double-hybrid (DSDPBEP86), being the superior model at the fifth rung of the Jacobi's ladder, was used as the reference. The atoms-in-molecule (AIM), alongside with the non-covalent interactions (NCIs) as visual extension had been utilized in the study of weak interactions and to affirm the degree of interactions between the clusters and the toxin. In all cases, this study suggests that the adsorption phenomena are best described as chemisorption due to the negative adsorption enthalpy observed. The mean absolute deviation (MAD) and root mean square deviation (RMSD) statistical approaches suggest the behavior of the possible adsorptions to be ranked as follows: PBE0-D3BJ (first rank), ωB97XD (second rank) and finally, M062X-D3BJ (third rank) with (MAD=0.7846, 0.7870 and 0.8402) and (RMSD=0.8924, 0.8946 and 0.9560), respectively. These results are consistent with those of the topological and the sensing parameters, hence, arriving at a conclusive scientific report that Mg12O12 and Mg12PO11 surfaces exhibit relatively better sensing performances for the trapping of melamine (MB).