Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Province Key Laboratory of Biomedical Materials and Chemical Measurement, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, P. R. China.
ACS Sens. 2023 Nov 24;8(11):4384-4390. doi: 10.1021/acssensors.3c01848. Epub 2023 Nov 14.
Fluoride ions are highly relevant in environmental and biological sciences, and there is a very limited number of established fluoride chemical sensors. Previous fluoride-selective optodes were demonstrated with metal-porphyrin as the ionophore and required a chromoionophore for optical signal transduction. We demonstrate here novel optical fluoride sensing with nano-optodes containing an aluminum-phthalocyanine complex (AlClPc) as the single active sensing component, simplifying the conventional ion-selective optodes approach. The fluoride nano-optodes were interrogated in the absorbance and fluorescence modes in the near-infrared region, with absorption around 725 nm and emission peaks at 720 and 800 nm, respectively. The nano-optodes exhibited a lower detection limit around 0.1 μM and good selectivity over a range of common anions including ClO, Cl, Br, I, SO, NO, and AcO. Furthermore, the nano-optodes were physically entrapped in agarose hydrogels to allow distance-based point-of-care testing (POCT) applications. The 3D networks of the agarose hydrogel were able to filter off large particulates in the samples without stopping fluoride ions to reach the nano-optodes. The fluoride concentrations in real samples including river water, mineral water, and groundwater were successfully determined with the distance-based sensing hydrogel, and the results agreed well with those from commercial fluoride electrodes. Therefore, the results in this work lay the groundwork for the optical detection of fluoride in environmental samples without very sophisticated sample manipulation.
氟离子在环境和生物科学中具有重要意义，但已建立的氟化学传感器数量非常有限。先前的氟选择型光导纤维已经证明了金属卟啉作为离子载体的作用，并且需要显色离子载体进行光学信号转导。在这里，我们展示了一种新型的光学氟传感，使用纳米光导纤维作为单一活性传感元件，其中包含铝酞菁络合物（AlClPc），简化了传统的离子选择性光导纤维方法。以近红外区域的吸收和荧光模式对氟化物纳米光导纤维进行了检测，其吸收约为 725nm，发射峰分别在 720nm 和 800nm。纳米光导纤维的检测下限约为 0.1μM，对包括 ClO、Cl、Br、I、SO、NO 和 AcO 在内的一系列常见阴离子具有良好的选择性。此外，纳米光导纤维被物理包埋在琼脂糖水凝胶中，以允许进行基于距离的即时护理测试（POCT）应用。琼脂糖水凝胶的 3D 网络能够过滤掉样品中的大颗粒，而不会阻止氟离子到达纳米光导纤维。成功地用基于距离的传感水凝胶测定了实际样品中的氟化物浓度，包括河水、矿泉水和地下水，并且结果与商业氟化物电极的结果非常吻合。因此，这项工作为在无需非常复杂的样品处理的情况下对环境样品中的氟化物进行光学检测奠定了基础。
