Abstract：
The purpose of this experimental and modeling research is to study the pH effect and to determine the surface coverage plus the adsorption constant (Ka) of bovine serum albumin (BSA) protein adsorbed on TiO2 anatase surface, respectively. In situ Fourier transform infrared-attenuated total reflection spectroscopy in a flow-through cell was used to study the BSA adsorption on porous TiO2 anatase films. The experiments were performed in water solution, under different pH values, at a concentration of 10-6 mol/l. Theoretically, we extended the two-state model, based on a system of coupled differential equations, by adding a desorption parameter Kd2, for unfolded state. The model was solved taking into account the adsorption (Ka), desorption (Kd1,2), transformation (Kf) coefficients, and the initial solution protein concentration (C0). The findings clearly illustrated that the solution pH drastically changed the behavior of BSA adsorption, whereas the mathematical analytical solutions allowed us to determine the native state (θ1), the unfolded state (θ2), and the full one (θ) surface coverages. Finally, a good application of the approximated model on the experimental work, expanded BSA adsorbed on TiO2 anatase at pH = 1.7, indicated a value of Ka = (408.36 ± 0.996) × 102 mol-1 l min-1.
摘要：
本实验和模型研究的目的是研究pH的影响，并确定表面覆盖率加上吸附在TiO2锐钛矿表面的牛血清白蛋白（BSA）蛋白的吸附常数（Ka），分别。在流通池中使用原位傅里叶变换红外衰减全反射光谱来研究BSA在多孔TiO2锐钛矿膜上的吸附。实验是在水溶液中进行的，在不同的pH值，浓度为10-6mol/l。理论上,我们扩展了两状态模型，基于耦合微分方程组，对于展开状态,通过添加解吸参数Kd2。考虑吸附(Ka)，对模型进行了求解，解吸(Kd1,2)，变换(Kf)系数，和初始溶液蛋白质浓度(C0)。研究结果清楚地表明，溶液的pH急剧改变了BSA的吸附行为，而数学解析解允许我们确定自然状态(θ1)，展开状态(θ2)，和完整的一个(θ)表面覆盖。最后,近似模型在实验工作中的良好应用，在pH=1.7时，吸附在TiO2锐钛矿上的膨胀BSA的值为Ka=（408.36±0.996）×102mol-1lmin-1。
