辣根过氧化物酶催化合成水溶性导电聚苯胺的研究

摘要

以辣根过氧化物酶(HRP)为催化剂、十二烷基硫酸钠(SDS)为模板研究了生物催化水溶性导电聚苯胺(PANI)的合成.探讨了反应体系的pH值、过氧化氢浓度和SDS浓度对聚合反应的影响,并研究了HRP催化苯胺聚合过程中性质的变化.紫外可见扫描光谱分析和电导率测定的结果表明,在以SDS为模板的条件下,HRP催化水溶性导电聚苯胺合成的最适pH值为2.0、最适的SDS和H2O2浓度都在20 mmol·L-1左右.测定HRP的活性发现,HRP在pH值低于2.0时其蛋白部分变性失活,但仍可催化导电聚苯胺的合成,推测HRP在催化导电聚苯胺的合成过程中主要依靠其活性中心的铁卟啉发挥作用.%The production of water-soluble conducting polyaniline catalyzed by horseradish peroxidase (HRP) in sodium dodecylsulfate (SDS) micellar solution at pH value of 1. 0～4.0 was reported. The influences of pH value, H2O2 concentration and SDS concentration on the polymerization of aniline had been explored. It was found that water-soluble conducting polyaniline could be produced at pH value of 1.0～2.0. The results were confirmed by UV-Vis spectra and conductivity determination, which also suggested the optimum pH value for this reaction was 2.0 and the optimum SDS cencentration and H2O2 concentration were both about 20 mmol · L-1. Results indicated that protein of HRP lost activity at low pH value below 2.0 in the presence of SDS.However, HRP could still catalyze the production of conducting polyaniline in SDS micellar solution even it was denatured. It was deduced that the catalytic ability of HRP on the polymerization of aniline came mainly from the iron porphyrin of HRP.