物理化学学报 >> 2010, Vol. 26 >> Issue (10): 2672-2678.doi: 10.3866/PKU.WHXB20101003

催化和表面结构 上一篇    下一篇

基于光波导分光光谱技术研究蛋白质与亚甲基蓝的竞争吸附行为

邓琳, 祁志美   

  1. 中国科学院电子学研究所, 传感技术国家重点实验室, 北京 100190
  • 收稿日期:2010-05-24 修回日期:2010-07-05 发布日期:2010-09-27
  • 通讯作者: 祁志美 E-mail:zhimei-qi@mail.ie.ac.cn
  • 基金资助:

    国家重点基础研究发展计划(973)(2009CB320300),国家自然科学基金(60978042)和中科院“百人计划”择优支持项目资助

Study of Competitive Adsorption Behavior of Protein andMethylene Blue by Optical Waveguide Spectroscopy

DENG Lin, QI Zhi-Mei   

  1. State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2010-05-24 Revised:2010-07-05 Published:2010-09-27
  • Contact: QI Zhi-Mei E-mail:zhimei-qi@mail.ie.ac.cn
  • Supported by:

    The project was supported by the National Key Basic Research Programof China (973) (2009CB320300), National Natural Science Foundation of China (60978042), and the BaiRenJiHua Programof Chinese Academy of Sciences.

摘要:

通过利用时间分辨光波导分光光谱技术原位测量从蛋白质-亚甲基蓝(MB) 混合水溶液吸附到亲水玻璃光波导表面的MB 可见光吸收谱, 观测到在溶液pH 值低于蛋白质等电点时MB 与牛血清蛋白(BSA) 以及MB 与血红蛋白(Hb) 存在竞争吸附行为, 进一步测得这种竞争吸附行为对蛋白质浓度十分敏感, 可以用于简单测定溶液中的蛋白质含量. 基于Langmuir 等温吸附理论推导出了两种分子竞争吸附的动力学方程, 并利用该动力学方程对实验测得的吸光度随时间变化曲线进行了最佳拟合, 揭示了玻璃表面吸附的MB 分子个数在达到最大值后随时间呈指数衰减, 同时得出拟合参数与蛋白质浓度呈准线性关系.

关键词: 光波导分光光谱技术, 竞争吸附, 亚甲基蓝, 蛋白质探测

Abstract:

We used time-resolved optical waveguide spectroscopy (OWGS) to in-situ measure visible absorption spectrum for methylene blue (MB) adsorbed ona hydrophilic glass waveguide from an aqueous solution containing proteins such as bovine serum albumin (BSA) and hemoglobin (Hb). The competitive adsorption of MB and the protein was detected at a solution pH lower than the isoelectric point of the protein. Since the competitive adsorption behavior of MB and the protein is very sensitive to the protein concentration, the protein content in the mixed solution was readily determined by time-resolved OWGS. In addition, a kinetic equation for the competitive adsorption of the two molecules was deduced based on the Langmuir adsorption isotherm. The best fit of the measured time course of the absorbance with the theoretical kinetic equation reveals that the number of MB molecules adsorbed on the surface exponentially decreases with time after reaching a maximum.A quasi-linear relationship between the fitting parameters and the protein concentration was also obtained.

Key words: Optical waveguide spectroscopy, Competitive adsorption, Methylene blue, Protein detection

MSC2000: 

  • O647