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）受体作为内分泌干扰物（EDCs）电化学检测化学传感器的分子识别元件。三嗪类除草剂如阿特拉津和西玛津（CAT）被选为内分泌干扰物，因为它们被广泛地用于农业领域和/或高尔夫球场。以CAT为模板分子，甲基丙烯酸（MAA）和二甲基丙烯酸乙酯（EDMA）分别为功能单体和交联单体制备MIP受体，NMR研究表明MAA中羧基质子和CAT中氨基质子在氯仿和DMF中发生化学位移。这些化学位移随着MAA/CAT的比值而变化，直到MAA/CAT达到7左右时，这种变化趋于稳定。因此，在氯仿和DMF中，七个MAA分子将与一个CAT分子相互作用。在氯仿中制备的CAT-MIP与非MIP的再结合没有差异。而在DMF中制备的CAT-MIP则表现出比non-MIP更强的结合能力，可用于选择性结合试验。CAT-MIP对CAT的选择性结合优于其他三嗪类化合物（莠去津和丙嗪）。汞齐化金电极对过氧化氢的电化学响应比金电极高。在pH 3-5下观察到CAT再活化。在较高pH下，观察到还原电流，而在较低pH下，质子再循环电流压倒CAT还原。在pH 3时，用汞齐化金电极观察到CAT的最大还原电流。CAT样品与MIP结合，用甲醇洗脱，电极检测。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.