Abstract Polycrystalline (poly) lanthanum fluoride (LaF3) Electrolyte-Insulator-Semiconductor (EIS) sensors can serve as a promising portable sensor platform for monitoring fluoride ion (F−) concentration due to their small size, fast response and simple fabrication method. The key to successful implementation is to consider and understand the effects of the measurement environment on the F− detection performance of actual analyte samples. Here, we propose a pathway for accurate F− analysis in tap water by using low concentration of the buffer solution. The F− sensing characteristics of the sensors are extensively investigated by varying the concentration of the total ionic strength adjustment buffer solution (TISAB). The sensors exhibit a high sensitivity of 50.2 mV/pF, a low limit of detection of 1.4 ppb, a small hysteresis voltage of 0.9 mV and a small drift rate of 0.60 mV/h. in the 100-times diluted TISAB (0.01 × TISAB). In addition, the poly LaF3 EIS sensors show highly selective detection of F− over others. When F− analysis of tap water is compared to a commercial F− ion selective electrode, the result is only different by 6.1% for the 0.01 × TISAB compared to 11.2% for 1 × TISAB. Thus, the dilution of TISAB can provide better measurement conditions for highly accurate F− analysis in actual sensor applications.

中文翻译：

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用于准确检测自来水中氟离子的缓冲溶液优化

摘要 多晶（聚）氟化镧（LaF3）电解质-绝缘体-半导体（EIS）传感器由于其体积小、响应速度快和制造方法简单，可作为一种有前途的便携式传感器平台，用于监测氟离子（F-）浓度。成功实施的关键是考虑和理解测量环境对实际分析物样品的 F− 检测性能的影响。在这里，我们提出了一种通过使用低浓度缓冲溶液在自来水中准确分析 F− 的途径。通过改变总离子强度调节缓冲溶液 (TISAB) 的浓度，对传感器的 F- 传感特性进行了广泛研究。该传感器具有 50.2 mV/pF 的高灵敏度、1.4 ppb 的检测下限、0 的小滞后电压。9 mV 和 0.60 mV/h 的小漂移率。在 100 倍稀释的 TISAB (0.01 × TISAB) 中。此外，聚 LaF3 EIS 传感器显示出对 F− 的高度选择性检测。当将自来水的 F− 分析与商用 F− 离子选择性电极进行比较时，0.01 × TISAB 的结果与 1 × TISAB 的结果仅相差 6.1% 和 11.2%。因此，TISAB 的稀释可以为实际传感器应用中的高精度 F− 分析提供更好的测量条件。