Adsorption of Hexoses\non the Ti<sub>2</sub>CO<sub>2</sub> MXene

In this study, we employed density functional theory\ncalculations\nto investigate the adsorption behavior of α and β isomers\nof d-glucopyranose, d-galactopyranose, d-fructopyranose, and d-mannopyranose on the Ti<sub>2</sub>CO<sub>2</sub> MXene surface, in order to understand the potential\nof this material for sensing sugars. The adsorption process was found\nto occur via strong noncovalent interactions, primarily through hydrogen\nbonding and with the hexoses oriented parallel to the surface. The\ncalculated adsorption energies vary between −0.78 (α-d-fructopyranose) and −1.00 eV (β-d-glucopyranose).\nImportantly, while the charge transfer was found to be negligible,\nthe work function of the material was found to change by up to 0.3\neV in the case of the compound that adsorbs most strongly, β-d-glucopyranose, while less important changes were found for\nthe other studied hexoses. We also explored the influence of defects\nin the MXene structure on the adsorption of β-d-glucopyranose\nand observed that oxygen or titanium vacancies enhance the adsorption\nstrength. These findings indicate that the Ti<sub>2</sub>CO<sub>2</sub> MXene is a promising candidate for selective glucopyranose sensing,\nwhich can be interesting for glucose detection applications.