The excess residues of fluoride ions cause serious human health problems, making their detection highly valuable. In this work, a whole-cell-based biosensor was presented for the detection of fluoride ions, which can inhibit the color reaction of 3,3′,5,5′,-tetramethylbenzidine (TMB) catalyzed by the CotA-laccase of spore surface. This reaction for the detection of fluoride ions could be read out through UV–vis spectrophotometer, smartphone, or standard colorimetric card within 10 min. Under optimum conditions, a linear range of 1–600 μmol L^–1 with a detection limit of 0.12 μmol L^–1 (3σ/k) was achieved for fluoride ions detection by using UV–vis spectrophotometer. The biosensor coupling with smartphone had a good linear response to fluoride ions concentration in the range of 5–600 μmol L^–1 with LOD of 0.90 μmol L^–1 (3σ/k). The standard colorimetric card can be directly used for recognizing the fluoride ions level via naked-eyes. A portable kit based on a colorimetric card and smartphone was developed and has been successfully applied for fluoride ions monitoring in surface waters and groundwater. This developed method has several advantages such as rapid, outstanding selectivity and anti-interference, low-cost, ease of operation and storage, and eco-friendliness, meeting the demands of point-of-care testing of fluoride ions and disease prevention.

氟离子的过量残留会导致严重的人类健康问题，因此其检测具有很高的价值。在这项工作中，提出了一种用于检测氟离子的全细胞生物传感器，该传感器可以抑制孢子 CotA-漆酶催化的 3,3',5,5',-四甲基联苯胺 (TMB) 的显色反应。表面。可以在 10 分钟内通过紫外-可见分光光度计、智能手机或标准比色卡读出这种用于检测氟离子的反应。在最佳条件下，线性范围为 1–600 μmol L ^–1，检测限为 0.12 μmol L ^–1(3σ/k) 是通过使用紫外-可见分光光度计检测氟离子获得的。与智能手机耦合的生物传感器对 5–600 μmol L ^–1范围内的氟离子浓度具有良好的线性响应，LOD 为 0.90 μmol L ^–1 (3σ/k)。标准比色卡可直接用于肉眼识别氟离子水平。开发了基于比色卡和智能手机的便携式套件，并已成功应用于地表水和地下水中的氟离子监测。该方法具有快速、选择性和抗干扰性强、成本低、操作和储存方便、环境友好等优点，满足了氟离子即时检测和疾病预防的需求。