Zhao Zi-Xia, Wang Hui-Cai, Qin Xia, Wang Xin-Sheng, Qiao Ming-Qiang, Anzai Jun-Ichi, Chen Qiang
The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, PR China.
Colloids Surf B Biointerfaces. 2009 Jun 1;71(1):102-6. doi: 10.1016/j.colsurfb.2009.01.011. Epub 2009 Jan 20.
Hydrophobins are small fungal proteins which self-assemble on interfaces and significantly change the surface wettability. The self-assembled film of hydrophobin HFBI on a gold surface improved the surface hydrophilicity with water contact angle changing from 73.8+/-1.8 degrees to 45.3+/-1.4 degrees . A quartz crystal microbalance (QCM) analysis indicated that the HFBI coverage density on a gold surface was 588 ng cm(-2), and the self-assembled film remained stable under different pH values ranging from 1 to 13. A hydrophilic protein such as choline oxidase (ChOx) was then successfully immobilized on the HFBI modified gold surface. To evaluate the bioactivity of immobilized enzyme, an amperometric choline biosensor was constructed based on the Gold/HFBI/ChOx electrode, which produced as large as 4578.27 nA response current by 0.238 microg immobilized ChOx, when saturated by choline substrate. Comparing with our choline biosensors previously reported, the HFBI self-assembled film exhibited excellent capability to preserve the bioactivity of ChOx, hence a great potential in electrochemical biosensing is suggested.
疏水蛋白是一类小型真菌蛋白，它们在界面上自组装并显著改变表面润湿性。疏水蛋白HFBI在金表面的自组装膜提高了表面亲水性，水接触角从73.8±1.8度变为45.3±1.4度。石英晶体微天平（QCM）分析表明，金表面上HFBI的覆盖密度为588 ng cm(-2)，并且自组装膜在pH值从1到13的不同范围内保持稳定。然后，一种亲水性蛋白，如胆碱氧化酶（ChOx），成功地固定在HFBI修饰的金表面上。为了评估固定化酶的生物活性，基于金/HFBI/ChOx电极构建了一种安培型胆碱生物传感器，当被胆碱底物饱和时，0.238μg固定化ChOx产生高达4578.27 nA的响应电流。与我们之前报道的胆碱生物传感器相比，HFBI自组装膜表现出优异的保持ChOx生物活性的能力，因此表明其在电化学生物传感方面具有巨大潜力。
