通过真空抽滤方法得到均匀致密的高导电多壁碳纳米管(MWCNTs)薄膜,利用聚二甲基硅氧烷(PDMS)对其进行封闭处理,制备出末端可裁切的PDMS基柔性碳纳米管薄膜电极,其裁切端面为电化学传感界面。在十六烷基三甲基溴化铵(CTAB)的增敏作用下,所制备的电化学传感器对双酚A(BPA)具有灵敏的电化学响应,其峰电流与BPA浓度在0.05~0.5μmol/L和0.5~12μmol/L范围内呈良好的线性关系,检测限为50nmol/L。通过电极末端的重复裁切可避免电极污染,并实现电极表面的快速更新和重复使用。对同一支电极进行13次连续裁切,用于10μmol/L BPA的检测,其相对标准偏差为3.4%。将该传感器应用于热敏纸样品中BPA的检测,加标回收率在95%~105%之间。
In this work,a reusable thin-film electrochemical sensor for the sensitive detection of bisphenol A(BPA)was developed.The sensor was constructed by firstly preparing multi-walled carbon nanotubes(MWCNTs)thin films through vacuum filtration and then sealing the MWCNTs film with polydimethlysiloxane(PDMS)to form a PDMS-MWCNTs thin-film electrode.The proposed electrochemical sensor showed a sensitive electrochemical response towards BPA with the enhancement effect of cationic surfactant cetyltrimethyl ammonium bromide(CTAB).The oxidation peak current of BPA linearly increased with its concentration in the range of 0.05-0.5μmol/L and 0.5-12μmol/L,along with a detection limit of 50nmol/L.The rapid regeneration and reusability of the electrode was realized by cutting and removing the fouled electrode area.The relative standard deviation of the same electrode with 13 successive cutting and measurements was 3.4%for 10μmol/L BPA.This electrochemical sensor was successfully applied to the detection of BPA in receipt paper samples,and acceptable recoveries in the range of 95%-105% were obtained.