104 MHz surface acoustic wave sensors, functionalized with two polypyrrole (PPy) imprinted polymers, were designed for lead ion detection in liquid media. The main difference between the two ionic imprinted polymers (IIP) is related to the nature of the chelating agent: L-Cysteine (L-Cys) for the former and acrylic acid (AA) for the latter. Performances of the IIPs based sensors were compared in terms of sensitivity, limits of detection (LOD), dissociation constants and selectivity. The gravimetric results indicated that both designed sensors can detect picomolar concentrations of lead ions. These values are, in fact, significantly inferior to the World Health Organization (WHO) maximum accepted limit in drinking water, and among the lowest LODs ever reported in the literature. The relevant dissociation constants, calculated from the most appropriate fits of the calibration curves, were estimated at: Kd $_{\textsf {1}} = (\textsf {1.1} \pm \textsf {0.4})\times \textsf {10}^{-\textsf {10}}$ M and Kd $_{\textsf {2}}= (\textsf {1.1} \pm \textsf {0.8})\times \textsf {10}^{-\textsf {5}}$ M for L-Cys-IIP/Pb²⁺ and Kd $_{\textsf {1}}= (\textsf {1.1} \pm \textsf {0.3})\times \textsf {10}^{-\textsf {13}}$ M and Kd $_{\textsf {2}}= (\textsf {5.9} \pm \textsf {1.8}) \times \textsf {10}^{-\textsf {10}}$ M for AA-PPy-IIP/ Pb²⁺, thus confirming the strong binding between the designed IIPs and lead ions. Selectivity tests were investigated with mercury, cadmium, copper, zinc, and nickel divalent ions, which largely coexist with lead ions in soils, rivers, and wastewaters.

中文翻译：

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L-半胱氨酸和丙烯酸印迹聚吡咯传感器的设计，用于简单和真实介质中铅离子的皮摩尔检测

104 MHz 表面声波传感器采用两种聚吡咯 (PPy) 印迹聚合物功能化，设计用于液体介质中的铅离子检测。两种离子印迹聚合物 (IIP) 之间的主要区别与螯合剂的性质有关：前者为 L-半胱氨酸 (L-Cys)，后者为丙烯酸 (AA)。在灵敏度、检测限 (LOD)、解离常数和选择性方面比较了基于 IIP 的传感器的性能。重量分析结果表明，两种设计的传感器都可以检测皮摩尔浓度的铅离子。事实上，这些值明显低于世界卫生组织 (WHO) 饮用水中的最大可接受限值，并且是文献中报道的最低 LOD 之一。相关的解离常数， $_{\textsf {1}} = (\textsf {1.1} \pm \textsf {0.4})\times \textsf {10}^{-\textsf {10}}$ M和Kd $_{\textsf {2}}= (\textsf {1.1} \pm \textsf {0.8})\times \textsf {10}^{-\textsf {5}}$ M 代表 L-Cys-IIP/Pb ²⁺和 Kd $_{\textsf {1}}= (\textsf {1.1} \pm \textsf {0.3})\times \textsf {10}^{-\textsf {13}}$ M和Kd $_{\textsf {2}}= (\textsf {5.9} \pm \textsf {1.8}) \times \textsf {10}^{-\textsf {10}}$ M 为 AA-PPy-IIP/Pb ²⁺，从而证实了设计的 IIP 和铅离子之间的强结合。对汞、镉、铜、锌和镍二价离子的选择性测试进行了研究，这些离子主要与土壤、河流和废水中的铅离子共存。