(632c) Effects of Pore Size and Protein Properties On Adsorption Kinetics of Proteins On Mesoporous Titanium Dioxide

Highly efficient biosensor is important in food, medical and environmental fields. The biocompatibility and selective protein adsorption provide mesoporous titanium dioxide as a potential candidate in biosensor applications. One unsolved fundamental issue for mesoporous titanium dioxide is how the adsorption kinetics of proteins depends on the pore size of the material, and the protein properties such as net charge and molecular shape. To shed light on this issue, we studied the adsorption kinetics of the proteins with various net charges and shapes on mesoporous titanium dioxide with pore sizes ranging from 3 to 30 nm by analyzing their residence times in high performance liquid chromatography. We selected three proteins: bovine serum albumin, lysosome and fibrinogen. They present different net charges and shapes in physiological condition. We prepared nine columns with titanium dioxide powders with desired pore sizes and measured the residence times of the above three proteins in the physiological condition. The pore size characteristics of mesoporous titanium dioxide were measured with N₂ adsorption and calculated with Brunauer–Emmett–Teller theory. The residence times of the respective proteins in a column prepared with commercial nonporous titanium dioxide powder is used as the control. From the variation of residence times of these proteins, we derived how the pore size, and the net charge and shape of protein affects the adsorption kinetics of proteins on mesoporous titanium dioxide.