聚对氨基苯磺酸-MoS2纳米片复合膜修饰玻碳电极溶出伏安法测定Pb2+

Stripping voltammetry detection of Pb using poly( amino benzene sulfonic acid)-MoS nanosheets composite membrane modified glassy carbon electrode

通过滴涂及电聚合的方式在玻碳电极(GCE)表面制备了二硫化钼(MoS2)-聚对氨基苯磺酸(pABSA)复合膜修饰电极,并通过循环伏安法(CV)和电化学交流阻抗法(EIS)对修饰电极进行了表征。该复合膜对Pb2+具有良好的催化活性,利用方波溶出伏安法(SWSV)对Pb2+在复合膜上的电化学行为进行了研究。在最优条件下,Pb2+的溶出峰电流值与其浓度在0.5 nmol/L^2.5μmol/L的范围内呈良好线性关系,R2=0.9983,检出限为0.1 nmol/L。同时探究了电解质种类、pH、富集时间、富集电位等因素对Pb(NO3)2溶出伏安响应信号的影响。对实际样品进行检测,加标回收率98.6%~101.2%。

A MoS2-poly( p-aminobenzene sulfonic acid) composite membrane modified electrode was fabricated by drop coating and electrochemical polymerization on a glassy carbon electrode( GCE),and was characterized by cyclic voltammetry( CV) and electrochemical impedance spectroscopy( EIS). The composite membrane exhibited a good catalytic activity for Pb2+and the electrochemical behavior of Pb2+on the film surface was investigated by using square wave dissolving voltammetry method( SWSV). It was found that the stripping peak current value of Pb2+was in good linear relationship with its concentration in the range from 0. 5 nmol/L to 2. 5 μmol/L under the optimized conditions. The limit of detection( LOD) was 0. 1 nmol/L. At the same time,the influence factors on the response signals of lead nitrate such as electrolyte type,pH,enrichment time,enrichment potential and other factors were investigated. The real samples were tested and the high recovery of 98. 6% ~ 101. 2% were obtained.