Analysis of the nature of interaction between AlN nanocage and ibuprofen using quantum chemical study

Density functional theory was used to study the adsorption behavior of ibuprofen (IBP) on an aluminum nitride (AlN) nanocage. The adsorption energy of IBP on the AlN surface was calculated to be about −29.43 kcal/mol in the most stable complex. Furthermore, the IBP concentration effect was examined on the adsorption behavior. We found that the IBP molecule adsorbed on the AlN nanocage through an electrostatic mechanism. Moreover, after IBP adsorption, the AlN HOMO-LUMO gap decreased significantly from 3.99 to 2.84 eV, and the work function value of AlN-IBP complex became smaller (by about 14.5%) compared to that of the pristine AlN nanocage. Thus, AlN might be an electronic or a work function-type sensor for IBP detection. Based on the polarizable continuum model calculations, the AlN-IBP complex in water medium was more stable compared to the gas phase. Our findings also revealed that the AlN nanocage would selectively identify the IBP molecule in the presence of environmental pollutants.