Development of A Sensing System for Endocrine Disrupting Chemicals Utilizing Nano Chemical Receptor Modified Sensor Chip

本研究利用分子印迹聚合物（MIP）受体作为化学传感器的分子识别元件，对内分泌干扰物（EDCs）进行电化学检测。选择阿特拉津和噻嗪（CAT）等三嗪类除草剂作为EDCs，是因为它们在农田和高尔夫球场中被广泛使用。以CAT为模板分子，以甲基丙烯酸（MAA）为功能单体，以二甲基丙烯酸乙酯（EDMA）为交联单体，制备MIP受体。核磁共振研究表明，MAA中的羧基质子和CAT中的氨基质子的化学位移在氯仿和DMF中相互作用。这些化学变化与MAA/CAT的比值有关。倾角趋于稳定，直到MAA/CAT在7左右。因此，在氯仿和DMF中，七个MAA分子会与一个CAT分子相互作用。用DMF或氯仿制备CAT-MIP。氯仿制备的CAT- mip与非mip的再结合没有差异。DMF中制备的CAT-MIP的结合量大于非mip，可用于选择性结合实验。CAT- mip与其他三嗪类（阿特拉津和丙嗪）选择性结合。采用金电极或汞化金电极对CAT进行电化学检测。汞化金电极对CAT的电化学响应比金电极高。在pH值3-5时，CAT降低。在较高pH下，质子还原电流大于CAT还原电流；在较低pH下，质子还原电流大于CAT还原电流。在pH值为3时，用汞化金电极观察了CAT的最大还原电流。将CAT样品与MIP结合，用甲醇洗脱，用电极检测。该检测对CAT具有选择性。

In this study, molecularly imprinted polymer (MIP) receptor was utilized as a molecular recognition element of chemical sensor based on electrochemical detection of endocrine disrupting chemicals (EDCs). Triazine herbicides such as atrazine and cimazine (CAT) were chosen as EDCs, because they are widely used in agricultural field and/or golf course. In order to prepare MIP receptor, CAT was used as a template molecule and methacrylic acid (MAA) and ethylenedimethacrylate (EDMA) were used as functional monomer and cross linking monomer, respectively.NMR studies demonstrated that the chemical shifts of carboxyl proton in MAA and amino proton in CAT interacted in chlorofolm and DMF. And these chemical shfts were inclinced as to the ratio of MAA/CAT. The inclination reached steady till the MAA/CAT came to around 7. Thus seven MAA molecules would interact with one CAT molecule in chloroform and DMF.CAT-MIP was prepared in DMF or chloroform. CAT-MIP prepared in chloroform showed no difference in the re-binding of CAT with non-MIP. However, CAT-MIP prepared in DMF showed its binding of more amount than non-MIP and it was served to the selective binding assay. CAT-MIP showed selective binding to CAT among other triazines(atrazine and propazine).Electrochemical detection of CAT was performed with gold or amalgamated gold electrode. Amalgamated gold electrode showed higher electrochemical response to CAT than a gold electrode. CAT recuction was observed at pH 3-5. At higher pH o reduction current was observed and at lower pH, proton recuction current overwhelmed the CAT reduction. At pH 3, the maximum reductive current of CAT was observed with an amalgamated gold electrode. CAT sample was bound to MIP and eluted by Methanol and it was detedted with the electrode. The detection was selective to CAT.