Enhancing the sensing performance of Al-modified graphene+ based sensor for anticancer medicinal molecules: A DFT study

Abstract

It is recently reported that a new pure carbon-based structure graphene+ (G+) exhibits more excellent properties such as buckling structure similar to penta-graphene and Dirac cones like graphene. In this work, a comprehensive exploration and comparison of the adsorption behaviors and sensing performances of optimal Al-doped G+ (Al_G+) and pristine G+ are explored by combing density functional theory with non-equilibrium Green’s function for anticancer drugs molecules, namely Cisplatin (CP), Hydroxyurea (HU), 5-fluorouracil (5-FU) and 6-Mercaptopurine (6-MP). Firstly, the stable and optimal structure of Al_G+ is obtained by sequentially substituting three distinct carbon atoms with Al atom. Moreover, it is found that the introduction of Al atom leads to the disappearance of the Dirac cones, resulting in a transition from semi-metallic to metallic. Subsequently, CP and HU exhibit physical adsorption, 5-FU and 6-MP are chemically adsorbed on the surface of G+ by high adsorption energy. However, the adsorption energy of Al_G+ for both CP and HU all increased by about 1.5 eV compared with G+. 5-FU and 6-MP are chemically adsorbed on Al_G+ by appropriate adsorption energies. Finally, the G+/Al_G+-based sensor is constructed to investigate the sensitivity of medicinal molecules according to chemisorption. It is seen that the sensitivity of the G+ to 5-FU and 6-MP is all less than 22 %. Although the Al_G+ has the sensitivity below 22 % for CP, HU and 5-FU, which has up to 62 % for 6-MP, more than 40 % higher than other medicinal molecules. Further, the high sensitivity and selectivity of Al_G+ towards 6-MP are elucidated through scattering states and transmission spectra of sensors. Upon the results, it suggests that Al_G+ has broad application prospects in multiple fields such as drug delivery and medicinal molecular detection especially for 6-MP.