响应苯酚类化合物辣椒过氧化物酶电极制备

Electrode of chilli-peroxidase of response to phenol

以辣椒为原料提取辣椒过氧化物酶(chill-peroxidase,CH-POD);以Pt片为基体,碳纳米管(car-bon nanotubes,CNTs)为电子载体,N,N-二甲基甲酰胺作为分散剂,微晶纤维素(microcrystalline cellu-lose,MC)作为载体包埋辣椒过氧化物酶制备成CH-POD-MC/CNTs/Pt电极。显微镜观察电极的形貌,循环伏安法考察响应苯酚的最适条件及其稳定性。结果表明,CH-POD-MC/CNTs/Pt具有传递电子的能力,在最适条件下对苯酚具有很强的响应性。其响应最佳条件为:12mL反应溶液中酶用量为100μL、反应液pH值为7.0。响应电流和苯酚浓度在扫描速度为50mV/s时二者的线性方程为:I(mA)=0.101369+0.01505C,线性响应范围为2～20mmol/L,线性相关系数为0.985,检出限为0.55mmol/L。制备的电极具有较强的稳定性,将制备的电极在4℃冰箱中放置7d,放置期间间歇性使用,其响应信号变化量没有超过初始信号的5%,并利用所制电极和分光光度法对4个工厂排放废水中苯酚浓度进行了平行测定,两种方法的相对偏差在-7.22%～9.0%。

A novel peroxidase electrode for the determination of phenol was fabricated by chill-peroxidase（CH-POD） extracted from chill.Carbon nanotubes（CNTs）,microcrystalline cellulose（MC）,N,N-dimethylformmide（DMF）,and CH-POD were modified on the surface of the platinum（Pt）.The profile of the peroxidase electrode,its the optimal condition of responsible to phenol and the stability were observed by optical microscope and cyclic voltammetry（CV）,respectively.Experimental results indicated that the electrode exhibited a good response to phenol.The optimal conditions of response were as following： 100μL chilli-peroxidase was used in 12mL reaction solution and pH was 7.0.With the scanning speed of 50mV/s the relationship between electric current and concentration of phenol can be described as： I（mA）=0.1429＋ 0.01297C.The linear response range was 2-20mmol/L with correlation coefficient of 0.996,detection limit was 0.25mmol/L.The experiment for the stability of the made electrode confirmed that the changing degree for the response signal was below 5% of the first signal when the electrode was intermittently used at 4℃ during placing period of 7d.The concentration of phenol of samples in waste water from four different factories was both determined by the peroxidase electrode and spectrophotometry.It demonstrated that the relative deviation of two methods is in the range from-7.22% to 0.74%.