QCM-D技术在不同润湿性表面蛋白吸附研究中的应用

Protein adsorption assay on surfaces with plasma treatment using quartz crystal microbalance-dissipation technique

目的:利用石英晶体微平衡-分散(QCM-D)技术研究白蛋白在高度亲水和高度疏水表面的吸附情况。方法:利用等离子聚合技术在8片圆形石英传感器上形成六甲基二硅氧烷薄膜聚合体薄膜,将4片上述试样采用低温氧等离子体轰击80 s,这两种表面分别代表高度疏水及高度亲水表面。将处理后的两种传感器装入QCM-D检测仪,将400 mg/L的牛血白蛋白溶液引入传感检测室,观察共振频率和离散因子随时间的变化,计算出蛋白的吸附量。结果:白蛋白在两种表面的吸附主要在早期10 s中完成,此后吸附变慢,在30 min左右达到吸附-离散平衡,30 min时白蛋白在高度疏水表面的平均吸附量为294.6 ng/cm2,而在高度亲水表面平均吸附量为235.1 g/cm2,两者有显著性差异。结论:QCM-D可以用来精确测定蛋白质在石英传感器表面的吸附,高度疏水性表面对白蛋白有较高的吸附能力。

AIM To analyze the protein adsorption behavior on surfaces with different surface wettability by quartz crystal microbalance - dissipation technique. METHODS ： Hexamethyldisiloxane polymer films were formed on QCM - D sensors and then 4 specimens were treated with oxygen plasma. The Hexamethyldi siloxane and oxygen plasma treated surfaces represented hydrophobic and hydrophilic surfaces respectively. Albumin adsorption on the two kinds of surfaces was observed by quartz crystal microbalance - dissipation technique. The concentration of albumin was 400 ppm. The frequency shift （Af） was measured and then protein adsorbed was calculated. RESULTS ： The fast adsorption phase complished within 10 seconds. Microbalance was achieved in 30 minutes, the mean adsorbed protein on the Hexamethy - ldisiloxane surfaces was 294.6ng/cm^2 , which was significantly higher than that on the plasma treated surface（235.1 n g/cm^2）. CONCLUSION： QCM -D technique can measure surface protein adsorption precisely. Albumin adsorbs more on hydrophobic surface than on hydrophilic one.