导电聚吡咯共聚物薄膜的功能基团种类对蛋白质吸附的影响

Effect of the Functional Group in the Conductive Pyrrole Copolymer Film on Protein Adsorption

导电聚合物由于其优越的稳定性和电化学性质,一直是蛋白质芯片敏感膜的研究热点.采用化学氧化聚合法分别制备出氨基和羧基功能化导电聚吡咯共聚物薄膜,通过调节体系单体比例(体积比)来改变导电共聚物的化学结构.采用傅里叶变换红外光谱表征了共聚物的化学组成,利用电化学循环伏安法考察共聚物薄膜的电化学活性变化.在此基础上,采用表面等离子谐振生化分析仪原位考察了牛血清白蛋白(BSA)在共聚物薄膜上的吸附动力学过程.由于共聚物薄膜上的功能基团的种类和含量不同,导致BSA吸附动力学和吸附量的差异.可以明显看出,蛋白质更容易在具有高的氨基密度或低的羧基密度的导电聚吡咯薄膜上进行吸附,随着氨基基团含量的增加,BSA在聚合物薄膜上的吸附量增大.相反,随着羧基基团含量的增大,BSA在共聚物薄膜上的吸附量减小.通过上述方法,可以控制蛋白质在导电聚合物上的吸附行为,进而为构建出更为敏感的、可精确控制的蛋白质芯片奠定基础.

Due to the high stability and outstanding electrochemical properties,the conductive polypyrrole has been become the research focus as the sensitive layer of protein sensors.In the present work,the conductive pyrrole copolymer films functionalized by carboxyl and amino groups were prepared via the oxidative polymerization.The chemical compositions of the copolymers could be adjusted by varying the monomer ratios.Fourier transform infrared spectroscopy was employed to determine the chemical composition of copolymer.While the electrochemical properties of such copolymer film was measured by cyclic voltammetry.On these bases,the adsorption kinetics of bovine serum albumin （BSA） onto the copolymer surface was in situ investigated by surface plasmon resonance of spectroscopy.The differences among the adsorption kinetics and the adsorbed amounts of BSA depended mainly on the type and content of the functional group in the copolymer.It demonstrates that BSA prefers to adsorb onto the polymer surface with higher content of amino groups and lower content of carboxyl groups.Moreover,the adsorbed amount of BSA in-creased with the increase of amino content in polymer film.On the contrary,it decreases with the increase in carboxyl content in polymer film.Therefore,the adsorption behavior of proteins onto the conductive polymers could be controlled in this way.Furthermore,it could be used to fabricate the more sensitive and controllable protein sensors.