Adaryan Sarah, Porter Erin B, Ardebili Haleh, Verduzco Rafael
Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States.
Mechanical and Aerospace Engineering, University of Houston, Houston, Texas 77004, United States.
ACS Appl Mater Interfaces. 2025 Apr 30;17(17):25582-25590. doi: 10.1021/acsami.5c03362. Epub 2025 Apr 17.
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants linked to adverse health effects, and there is a need for sensors that can detect PFAS in challenging environments. Electrochemical sensors offer significant potential for achieving cost-effective, rapid, and real-time detection of PFAS, particularly in comparison to current detection techniques, which rely on costly chromatographic methods. Here, we report that organic electrochemical transistors (OECTs) containing a molecularly imprinted polymer (MIP) gate electrode can selectively detect perfluorooctanoic acid (PFOA) in seawater. We prepared a molecularly imprinted polyaniline (PANI) gate electrode by polymerizing aniline onto filter paper in the presence of PFOA, followed by rinsing to remove the PFOA. When used as a gate electrode in an organic electrochemical device (OECT), the presence of PFOA produced a measurable change in the OECT source-drain current due to adsorption of PFOA onto the gate electrode, which reduced capacitance and increased impedance. Other molecules produced a weak or no response. Specifically, we show that the device responds strongly to PFOA but only weakly to perfluoropropionic acid (PFPrA), perfluorohexanoic acid (PFHxA), and surfactant 4-dodecylbenzenesulfonic acid (DBSA). The device is also able to selectively detect PFOA in mixtures containing these other PFAS or surfactants. We achieved a detection limit of 1.6 parts per trillion (ppt) or 3.86 × 10 M, below the regulatory advisory level of 70 ppt set by the United States Environmental Protection Agency for PFOA. This work demonstrates low-cost sensors capable of rapid and molecularly specific detection of PFOA, which can potentially lead to low-cost sensors for monitoring the concentrations of PFOA and other PFAS in seawater and other challenging environments.
全氟和多氟烷基物质（PFAS）是与不良健康影响相关的持久性环境污染物，因此需要能够在具有挑战性的环境中检测PFAS的传感器。电化学传感器在实现经济高效、快速且实时的PFAS检测方面具有巨大潜力，特别是与当前依赖昂贵色谱方法的检测技术相比。在此，我们报告含有分子印迹聚合物（MIP）栅电极的有机电化学晶体管（OECT）能够选择性地检测海水中的全氟辛酸（PFOA）。我们通过在PFOA存在下将苯胺聚合到滤纸上，然后冲洗以去除PFOA，制备了分子印迹聚苯胺（PANI）栅电极。当用作有机电化学器件（OECT）的栅电极时，由于PFOA吸附到栅电极上，导致OECT源漏电流发生可测量的变化，这降低了电容并增加了阻抗。其他分子产生的响应较弱或无响应。具体而言，我们表明该器件对PFOA有强烈响应，但对全氟丙酸（PFPrA）、全氟己酸（PFHxA）和表面活性剂4-十二烷基苯磺酸（DBSA）只有微弱响应。该器件还能够在含有这些其他PFAS或表面活性剂的混合物中选择性地检测PFOA。我们实现了1.6万亿分之一（ppt）或3.86×10⁻¹² M的检测限，低于美国环境保护局为PFOA设定的70 ppt的监管咨询水平。这项工作展示了能够快速且分子特异性检测PFOA的低成本传感器，这有可能导致用于监测海水和其他具有挑战性环境中PFOA和其他PFAS浓度的低成本传感器。
