Nanobioelectronics and Biosensor Group , Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, The Barcelona Institute of Science and Technology , Campus UAB, Bellaterra , 08193 , Barcelona , Spain.
Faculty of Biosciences and Technologies for Food, Agriculture and Environment , University of Teramo , via R. Balzarini 1 , 64100 Teramo , Italy.
Anal Chem. 2018 May 1;90(9):5850-5856. doi: 10.1021/acs.analchem.8b00389. Epub 2018 Apr 11.
Electrochromic effect and molecularly imprinted technology have been used to develop a sensitive and selective electrochromic sensor. The polymeric matrices obtained using the imprinting technology are robust molecular recognition elements and have the potential to mimic natural recognition entities with very high selectivity. The electrochromic behavior of iridium oxide nanoparticles (IrOx NPs) as physicochemical transducer together with a molecularly imprinted polymer (MIP) as recognition layer resulted in a fast and efficient translation of the detection event. The sensor was fabricated using screen-printing technology with indium tin oxide as a transparent working electrode; IrOx NPs where electrodeposited onto the electrode followed by thermal polymerization of polypyrrole in the presence of the analyte (chlorpyrifos). Two different approaches were used to detect and quantify the pesticide: direct visual detection and smartphone imaging. Application of different oxidation potentials for 10 s resulted in color changes directly related to the concentration of the analyte. For smartphone imaging, at fixed potential, the concentration of the analyte was dependent on the color intensity of the electrode. The electrochromic sensor detects a highly toxic compound (chlorpyrifos) with a 100 fM and 1 mM dynamic range. So far, to the best of our knowledge, this is the first work where an electrochromic MIP sensor uses the electrochromic properties of IrOx to detect a certain analyte with high selectivity and sensitivity.
电致变色效应和分子印迹技术已被用于开发一种灵敏且选择性高的电致变色传感器。印迹技术获得的聚合物基质是坚固的分子识别元件，具有模拟具有非常高选择性的天然识别实体的潜力。氧化铱纳米粒子（IrOx NPs）作为物理化学换能器的电致变色行为与作为识别层的分子印迹聚合物（MIP）一起，导致检测事件的快速和高效转换。该传感器使用丝网印刷技术制造，以氧化铟锡作为透明工作电极；IrOx NPs 在电极上电沉积，然后在分析物（毒死蜱）存在下进行聚吡咯的热聚合。使用了两种不同的方法来检测和定量农药：直接目视检测和智能手机成像。应用不同的氧化电位 10 秒导致颜色变化与分析物的浓度直接相关。对于智能手机成像，在固定电位下，分析物的浓度取决于电极的颜色强度。电致变色传感器以 100 fM 和 1 mM 的动态范围检测到高毒性化合物（毒死蜱）。到目前为止，据我们所知，这是第一个使用 IrOx 的电致变色特性来检测具有高选择性和灵敏度的特定分析物的电致变色 MIP 传感器的工作。
