Adsorption ability of graphitic carbon nitride C6N6 toward temozolomide and thalidomide drugs: a DFT study

DFT/wB97XD/6-311G(d,p) theoretical level is used herein to probe the adsorption ability of the 2D g-C₆N₆ nanomaterial toward thalidomide (TLD) and temozolomide (TMZ) drugs. Thereby, parameters like adsorption and Gibbs free energies describing the interaction between the adsorbent and each analyte, as well as topological analyses, and electronic parameters are determined in both gas and water phases. Our findings revealed that g-C₆N₆ can adsorb both drugs through an exergonic reaction, the molecular complex of TMZ being the most stable with an adsorption energy of −30.85 kcal/mol. Furthermore, only vdW type interactions are identified between the adsorbent and each drug during the adsorption process. The value of the change in the HOMO–LUMO energy gap of the adsorbent upon adsorption shows that unlike TMZ, the nanomaterial is seemingly not sensitive to TLD. This observation is further confirmed by the density of states of the nanomaterial which are almost not affected by the adsorption of TLD, unlike that of TMZ. These outcomes suggest that g-C₆N₆ is likely to adsorb TMZ but is unlikely to be used for the detection the TLD drug.