Institute of Chemistry, University of Campinas - UNICAMP, Campinas, Brazil.
Anal Chim Acta. 2011 Jun 10;695(1-2):44-50. doi: 10.1016/j.aca.2011.03.018. Epub 2011 Mar 12.
In this study, a novel sensitive molecularly imprinted electrochemical sensor was constructed for the selective detection of chlorogenic acid (CGA) by deposition of a molecularly imprinted siloxane (MIS) film, prepared by sol-gel process, onto Au bare electrode surface. Initially, a (3-mercaptopropyl)siloxane layer (MSL) was formed on the Au bare surface, followed by a siloxane layer obtained from the acid-catalyzed hydrolysis/condensation of a solution constituted by tetraethoxysilane (TEOS), phenyltriethoxysilane (PTEOS), 3-(aminopropyl)trimethoxysilane (APTMS) and CGA, as a molecular template. After the GCA extraction the MIS imprinted film was electrochemically characterized using differential pulse voltammetry (DPV). The MIS/Au sensor was tested in a solution of the CGA template and other similar molecules. This electrode displayed excellent selectivity towards CGA when compared with structurally similar molecules. Under optimized experimental conditions, the peak current response of the sensor for CGA was linear from 5.0 × 10(-7)mol L(-1) to 1.4 × 10(-5)mol L(-1), and the detection limit was 1.48 × 10(-7)mol L(-1). The MIS/Au sensor was successfully applied for the determination of CGA in coffee and tea samples.
在这项研究中，通过溶胶-凝胶过程在金裸电极表面上沉积分子印迹硅氧烷（MIS）膜，构建了一种用于选择性检测绿原酸（CGA）的新型灵敏分子印迹电化学传感器。最初，在 Au 裸表面上形成（3-巯丙基）硅氧烷层（MSL），然后通过酸性催化水解/缩合由四乙氧基硅烷（TEOS）、苯三乙氧基硅烷（PTEOS）、3-（氨丙基）三甲氧基硅烷（APTMS）和 CGA 组成的溶液获得硅氧烷层作为分子模板。在提取 GCA 后，使用差分脉冲伏安法（DPV）对 MIS 印迹膜进行电化学表征。在 CGA 模板和其他类似分子的溶液中测试了 MIS/Au 传感器。与结构相似的分子相比，该电极对 CGA 表现出优异的选择性。在优化的实验条件下，传感器对 CGA 的峰电流响应从 5.0×10(-7)mol L(-1)线性到 1.4×10(-5)mol L(-1)，检测限为 1.48×10(-7)mol L(-1)。MIS/Au 传感器成功应用于咖啡和茶样品中 CGA 的测定。
