DFT study on the adsorption of 5-fluorouracil on B₄₀, B₃₉M, and M@B₄₀ (M = Mg, Al, Si, Mn, Cu, Zn)

Based on density functional theory, the adsorption behavior of 5-fluorouracil (5-Fu) on B₄₀ and its derivatives has been explored. It was observed that 5-Fu prefers to combine with the corner boron atom of the B₄₀ cage via one of its oxygen atoms, forming a strong polar covalent B-O bond. The adsorption energy of 5-Fu on B₄₀ was calculated to be -11.15 kcal mol^-1, and thus, it can be duly released from B₄₀ by protonation in the slightly acidic environment of tumor tissue, which makes for reducing the toxic and side effects of this drug. Additionally, the substituent and embedding effect of Mg, Al, Si, Mn, Cu, and Zn atoms on the drug delivery performance of B₄₀ have been also considered. We hope this work could offer some implications for the potential application of boron-based nanomaterials, such as B₄₀ in drug delivery.