One of the major challenges in targeted drug delivery to cancer cells is the practical use of high-precision drug carriers. Extensive theoretical research has been done in this field. Among these studies, the use of harmless nanoclusters has attracted the attention of many researchers. Among them, boron phosphide nanoclusters have also received more attention. In this regard, in this research, the adsorption, thermodynamic, and quantum chemical study of all the designed complexes of 5-Fluorouracil (5-FU) anticancer drug with the pristine and Sc- and Ti-doped boron phosphide nanocage ( B12P12) in the presence of static electric field ( SEFz+0.01, SEFz+ 0.02. SEFz+ 0.03, SEFz+ 0.04 a.u.) have been carried out with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) at the ωB97XD/Lanl2DZ level of theory at 303.15 K. The adsorption energy (Eads) and ΔH values of all studied configurations are exothermic and with increasing the strength of the static electric field (SEF) from 0.01 to 0.04 a.u, decrease significantly from the original state. The ScB11P12 is a good adsorbent of the 5-FU drug in the gas phase and is suitable for drug delivery in a water solvent. The molecular electrostatic potential (MEP) and QNBO results indicate that the surface of the 5-FU drug in the 5-FU&nanocage complex is suitable for attacking the nucleophilic compounds and it will mostly attack the sites of the cell that has a negative charge and is nucleophilic. Further, analysis of frontier molecular orbital, reduced density gradient, TD-DFT, electron localized function (ELF), and atom in the molecule (AIM) suggested that the Sc- and Ti-doped B12P12 and the presence of static electric field are efficient candidates for 5-FU drug delivery and sensitive sensor.
