Fakultät Physik/DELTA , Technische Universität Dortmund , 44221 Dortmund , Germany.
Institute of Electronic Devices , University of Wuppertal , 42119 Wuppertal , Germany.
Langmuir. 2018 May 15;34(19):5403-5408. doi: 10.1021/acs.langmuir.8b00280. Epub 2018 May 1.
We present an in situ X-ray reflectivity study of the adsorption behavior of the protein lysozyme on titanium oxide layers under variation of different thermodynamic parameters, such as temperature, hydrostatic pressure, and pH value. Moreover, by varying the layer thickness of the titanium oxide layer on a silicon wafer, changes in the adsorption behavior of lysozyme were studied. In total, we determined less adsorption on titanium oxide compared with silicon dioxide, while increasing the titanium oxide layer thickness causes stronger adsorption. Furthermore, the variation of temperature from 20 to 80 °C yields an increase in the amount of adsorbed lysozyme at the interface. Additional measurements with variation of the pH value of the system in a region between pH 2 and 12 show that the surface charge of both protein and titanium oxide has a crucial role in the adsorption process. Further pressure-dependent experiments between 50 and 5000 bar show a reduction of the amount of adsorbed lysozyme with increasing pressure.
我们通过原位 X 射线反射率研究，展示了在不同热力学参数（如温度、静水压力和 pH 值）下，蛋白质溶菌酶在二氧化钛层上的吸附行为。此外，通过改变硅片上二氧化钛层的厚度，我们研究了溶菌酶吸附行为的变化。总的来说，与二氧化硅相比，我们确定在二氧化钛上的吸附较少，而增加二氧化钛层的厚度会导致更强的吸附。此外，温度从 20°C 到 80°C 的变化导致界面处吸附的溶菌酶数量增加。在 pH 值为 2 到 12 之间的系统变化的附加测量表明，蛋白质和二氧化钛的表面电荷在吸附过程中起着至关重要的作用。进一步在 50 到 5000 巴之间的压力依赖性实验表明，随着压力的增加，吸附的溶菌酶数量减少。
