多糖激活的酪氨酸酶生物电极测定酚类的研究

STUDY ON THE DETERMINATION OF PHENOLS WITH TYROSINASE BASED BIOSENSOR ACTIVATED BY POLYSACCHARIDE

研制了以麦芽糊精作为酪氨酸酶的激活剂 ,采用Nafion117膜抗阴离子干扰 ,聚乙烯亚胺 (PEI)作包埋剂以抗阳离子干扰的酪氨酸酶碳糊电极。工作电位为 - 10 0mV [vs.Hg/Hg2 Cl2(s) ],pH为 5 .4 0 ,测量时间为 1.0min。在此测量条件下 ,电极对苯酚的检出限为 5 .0× 10 - 8mol·L- 1,线性范围为 2 .0× 10 - 7～ 5 .0× 10 - 5mol·L- 1,RSD为 1.2 %。用所研制电极测定炼油废水中酚的含量 ,加标回收率为 10 0 .7%。

The preparation of the tyrosinase based paste carbon electrode activated by maltodextrin used as amperometric biosensor for the determination of phenols was described in this paper. Polyethyleneimide (PEI) was mixed with the tyrosinase solution to prevent the interferences of co existing cations, and Nafion 117 was used as a selective membrane to prevent the interferences of anions. Working conditions of the biosensor taken were as follows: working potential: -100mV [ vs. Hg/Hg 2Cl 2(s)]; pH 5.40; time of measurement 1.0min. Under the working conditions described, the detection limit of the biosensor to phenol achieved to a value of 5.0×10 -8 mol·L -1 . Linear relationship was obtained in the range of 2.0×10 -7 mol·L -1 to 5.0×10 -5 mol·L -1 of phenol. Value of RSD ( n =6) of 1.2% was obtained in the analysis of waste water, and recoveries were in the range 97.7% to 102.3%. This method has been used satisfactorily in the analysis of waste water from a petrochemical plant.