近些年,具有电活性的聚合物在生物分子吸附材料方面的应用越来越广.而导电聚合物的前聚体化合物的合成(如带吡咯基团的聚合物)对于生物分子的吸附研究非常重要.详细研究了牛血清白蛋白(BSA)在导电聚合物前聚体—聚丙烯酰吡咯(PAP)表面上的吸附规律.首先,采用自由基聚合方法合成PAP,通过spin-coating方法将PAP涂覆到50nm厚的金膜上,制备出均匀聚合物薄膜.然后,采用傅立叶转换红外光谱(FT-IR)和X射线光电子能谱(XPS)对PAP的化学结构及元素构成进行了分析,同时考察了PAP膜在不同pH值的生物缓冲液环境中的水接触角.在详细研究了聚合物膜的化学结构和表面性质之后,采用表面等离子体谐振仪(SPR)原位监测BSA在PAP上的吸附动力学过程,发现其吸附行为主要受缓冲液的pH值和BSA浓度的影响.在不同生物缓冲液环境下,蛋白质和聚合物膜之间的各种作用力会发生变化,最终导致蛋白质吸附行为以及吸附量的不同,这为以后制备更加敏感的导电蛋白质芯片奠定了基础.
The adsorption behavior of bovine serum albumin (BSA) on poly(acryloyl pyrrole) (PAP) was investigated in detail. Firstly, PAP, which was polymerized by free radical polymerization, was spin-coated onto 50 nm thick Au films to form the homogeneous surfaces. Afterwards, the chemical structures and group contents were characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). And the surface wettability of PAP in buffer solutions with different pH values was detected by the contact angle measurement. Secondly, the adsorption behavior of BSA on PAP was studied in situ by surface plasmon resonance spectroscopy (SPR). Herein, the factors to affect the adsorption of protein mainly include the pH values of buffer solutions and concentration of BSA used. The interactions between the protein molecules and polymer films changed in various buffer solution circumstances. Consequently, the adsorption behavior and the adsorbed amounts would be varied. PAP could be supplied as a promising material for fabricating more sensitive protein biochips in the recent future.