Computational Nanomaterials Design: towards the Realization of Nanoparticle use in Radiotherapy Case Study 2: Adsorption states of At on Au (111) Surface

Astatine-211 (211At or simply At) used as an α particle emitter is currently gaining as treatment method for cancer cells. It must however be attached to a carrier to facilitate the treatment process. Gold nanoparticle is a good candidate that has been used in several tests. Knowing the physics behind the adsorption of astatine on gold nanoparticles would be advantageous in designing a more optimal method for such applications. We therefore performed density functional theory calculation on astatine adsorption on gold (111) surface to understand both the mechanism of astatine bonding with gold and the strength of the bonding. We found the mechanism of adsorption to be the hybridization between the 6p orbital of astatine and the 5d and 6s orbitals of the gold. We also found the adsorption strength of astatine on gold to be -1.43 eV at the fcc hollow site. Both results provide us with a good starting point towards our goal of designing an optimized gold nanoparticle for radiotherapy.