School of Civil Engineering, c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
Anal Chem. 2021 Jun 1;93(21):7588-7595. doi: 10.1021/acs.analchem.0c05422. Epub 2021 May 19.
The solid-contact ion-selective electrodes (SC-ISEs) are a type of potentiometric analytical device with features of rapid response, online analysis, and miniaturization. The state-of-the-art SC-ISEs are composed of a solid-contact (SC) layer and an ion-selective membrane (ISM) layer with respective functions of ion-to-electron transduction and ion recognition. Two challenges for the SC-ISEs are the water-layer formation at the SC/ISM phase boundary and the leaking of ISM components, which are both originated from the ISM. Herein, we report a type of SC-ISE based on classic Li-ion battery materials as the SC layer without using the ISM for potentiometric lithium-ion sensing. Both LiFePO- and LiMnO-based SC-ISEs display good Li sensing properties (sensitivity, selectivity, and stability). The proposed LiFePO electrode exhibits comparable sensitivity and a linear range to conventional SC-ISEs with ISM. Owing to the nonexistence of ISM, the LiFePO electrode displays high potential stability. Besides, the LiMnO electrode shows a Nernstian response toward Li sensing in a human blood serum solution. This work emphasizes the concept of non-ISM-based SC-ISEs for potentiometric ion sensing.
固体接触离子选择性电极 (SC-ISE) 是一种电位分析装置，具有快速响应、在线分析和小型化等特点。最先进的 SC-ISE 由固体接触 (SC) 层和离子选择性膜 (ISM) 层组成，分别具有离子-电子转换和离子识别的功能。SC-ISE 面临的两个挑战是 SC/ISM 相界面处水层的形成和 ISM 成分的泄漏，这两者都源自 ISM。本文报道了一种基于经典锂离子电池材料作为 SC 层的 SC-ISE，而不使用 ISM 进行锂离子电位传感。基于 LiFePO 和 LiMnO 的 SC-ISE 均表现出良好的 Li 传感性能（灵敏度、选择性和稳定性）。所提出的 LiFePO 电极在灵敏度和线性范围方面与具有 ISM 的传统 SC-ISE 相当。由于不存在 ISM，LiFePO 电极表现出高的电位稳定性。此外，LiMnO 电极对人血清溶液中的 Li 传感呈现出 Nernstian 响应。这项工作强调了非 ISM 基 SC-ISE 用于电位离子传感的概念。
