基于PVC薄膜的汞离子光寻址电位传感器

Mercury ion selective light addressable potentiometric sensor based on PVC membrane

通过不同浓度溶液的试验,对一种新型聚氯乙稀(PVC)薄膜汞离子敏感光寻址电位传感器进行了研究,PVC薄膜中的敏感物为5-amino-1,3,4-thiadiazole-2-thiol.采用硅烷化反应对光寻址电位传感器进行表面修饰,硅烷化前后的器件对单位pH(氢离子)的灵敏度分别为每67.299mV和4.9996mV,线性相关系数分别为0.9831和0.9877.PVC膜成聚后,该传感器对汞离子有选择性的电位响应特性,显示了良好的重复性和稳定性,单位pHg(汞离子)的灵敏度为15.381mV,线性相关系数为0.9629,对其他离子的抑制比大于4.实验得到的检出下限为1.57μg/L,响应时间为2～4s,适用pH范围为3～6.

A novel polyvinyl chloride（PVC） thin-film light addressable potentiometric sensor sensitive to mercury （Ⅱ） ion was tested by gradient concentrations. PVC matrix with 5-amino-1,3,4-thiadiazole-2-thiol was prepared and used as target material. Light addressable potentiometric sensor（LAPS） sensor was chemically modified by silanization. The sensitivities before and after the reaction are 67.299 mV per pH and 4.999 6 mV per pH,the linear correlations are 0.983 1 and 0.987 7,respectively. Once PVC membrane was deposited,Hg2＋ sensitive LAPS exhibits a good stability and repetition. The sensitivity of the potentiometric response shows the slope of 15.381 mV per pHg. The detection limit of the sensor was 1.57 μg/L. The response time maintained 2-4 s,and the application range of pH was located between 3-6.