Understanding Titanium Dioxide Surface Chemistry for Biomolecule Adsorption: Experiments and Molecular Dynamics Simulations

The behavior of surface water, especially the
adsorption and dissociation characteristics, is a key to
understanding and promoting photocatalytic and biomedical
applications of titanium dioxide materials. A knowledge of these effects and a strategic optimization are important in many applications: examples include biochemical sensing and separation, cell imaging, in vitro and in vivo targeted drug delivery, cancer therapy, toxic species removal from air, remediation of soils and ground water. Using molecular
dynamics simulations with the ReaxFF force field and experimental techniques, we have studied the following systems to understand how surface chemistry affects adsorption of biomolecules at TiO₂ surfaces: (a) water/TiO₂; (b) water/amino acid/TiO₂; (c) bovine serum albumin/water/TiO₂. The results show that TiO₂ surfaces demonstrate different reactivity for water dissociation. The resulted TiO₂ surface chemistry change, the surface hydroxyl groups due to water dissociation, significantly affects the interaction of amino acid and bovine serum albumin with TiO₂ materials.

1. Liangliang Huang, Keith E. Gubbins, Licheng Li and Xiaohua Lu, “Water on Titanium Dioxide Surface: A Revisiting by Reactive Molecular Dynamics Simulations”, Langmuir, 2014, 30, 14832.
2. Chang Liu, Yanhua Guo, Qiliang Hong, Chao Rao, Haijuan Zhang, Yihui Dong, Liangliang Huang, Xiaohua Lu, and Ningzhong Bao, “Bovine Serum Albumin Adsorption in Mesoporous Titanium Dioxide: Pore Size and Pore Chemistry Effect”, Langmuir, 2016, 32, 3995.