Detection of Li⁺ ions is vital due to their applications as therapeutic drugs in medicine. In addition, finding Li⁺ in geothermal brines is gaining interest because of its application in energy storage systems. Monitoring Li⁺ levels in an aqueous environment can be achieved using chemical sensors. Solid-contact sensors (SCS) have attracted significant attention because of their portability, high sensitivity and lack of requirement of calibration. However, most solid-contact sensors suffer from low stability, especially in the long term. As a result, ion-to-electron transducers have been utilized to mitigate this problem. Recently Metal-Organic Frameworks (MOFs) have proven to be excellent candidates for use as ion-to-electron transducers in SCSs. In this study, we have used Ni-HAB MOF to produce a highly stable Li⁺ selective electrode. Increasing the thickness of the MOF to 3.28 µm enhanced the sensor's capacitance 100-fold leading to the lowest drift in Li⁺ SCSs reported in the literature, $1.15\times {10}^{-6}$ mV/h with a low limit of detection (LOD) of $9.94\times {10}^{-7}M$ and a 57.6 mV/dec sensitivity. The sensor exhibited a linear output and a fast response time of less than 1 s. In addition, the sensor developed was used in a real brine to detect the concentration of Li⁺ ions, where the obtained results were in good agreement with the actual concentration of Li⁺ ions. This paper offers a solution for the persistent issues of solid-contact sensors such as drift, response time, and limit of detection and paves the way for the miniaturization of sensors to be used in real-life applications.

李的检测⁺离子是由于他们的应用程序作为治疗药物在医学上是至关重要的。此外，由于其在储能系统中的应用，在地热卤水中发现 Li ⁺也引起了人们的兴趣。监控李⁺水环境中的水平可以使用化学传感器来实现。固体接触传感器（SCS）因其便携性、高灵敏度和无需校准而备受关注。然而，大多数固体接触式传感器的稳定性较低，尤其是从长远来看。因此，已经使用离子到电子换能器来缓解这个问题。最近，金属有机框架 (MOF) 已被证明是 SCS 中用作离子到电子传感器的绝佳候选材料。在这项研究中，我们使用 Ni-HAB MOF 来生产高度稳定的 Li ⁺选择性电极。将 MOF 的厚度增加到 3.28 µm，可将传感器的电容提高 100 倍，从而使文献中报道的Li ⁺ SCS漂移最低，$1.15\times {10}^{-6}$ mV/h，检测下限 (LOD) 为 $9.94\times {10}^{-7}米$和 57.6 mV/dec 的灵敏度。该传感器表现出线性输出和小于 1 秒的快速响应时间。此外，开发的传感器在实际盐水中用于检测Li ⁺离子的浓度，获得的结果与Li ⁺离子的实际浓度非常吻合。本文为固体接触传感器的持续问题（如漂移、响应时间和检测限）提供了解决方案，并为在实际应用中使用的传感器小型化铺平了道路。