Ir-decorated gallium nitride nanotubes as a chemical sensor for recognition of mesalamine drug: a DFT study

We employed density functional theory to inspect the impact of Ir-decoration on the sensing performance of a GaN nanotube (GaNNT) in the detection of mesalamine (MA). The interaction of the pristine GaNNT with MA was found to be weak, and the sensing response was approximately 4.3. Decorating an Ir atom into the GaNNT surface increased the adsorption energy (E ad) of MA from −6.7 to −23.8 kcal/mol. The sensing response significantly increased to 89.4 after decorating the Ir atom. A short recovery time of 22.0 s was found for the desorption of MA from the surface of the Ir-decorated GaNNT at 298 K. The water solvent reduced E ad of MA to −19.8 kcal/mol. Thus, we concluded that the Ir-decorated GaNNT might be a highly sensitive MA sensor with a short recovery time.