Chen Zixu, Sun Ruixue, Feng Shengyu, Wang Dengxu, Liu Hongzhi
National Engineering Research Center for Colloidal Materials & Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):11104-11114. doi: 10.1021/acsami.0c01342. Epub 2020 Feb 21.
Developing a chemosensor for rapid, sensitive, and visual detection of iodide (I) by a simple synthetic strategy is still challenging. Herein, we report a highly efficient iodide sensor by simply introducing ionic imidazolium groups into the porous network. This sensor, that is, a fluorescent ionic porous framework (IPF), was prepared by the quaternization reaction of octa((benzylchloride)ethenyl)silsesquioxane and 1,4-bis(1-imidazole-1-yl)benzene and exhibited moderate porosity with a Brunauer-Emmett-Teller surface area of 379 m g and blue fluorescence when excited by UV light. The IPF suspension in water can detect I with high sensitivity and selectivity among various anions and quick response by fluorescence quenching. In contrast to no response toward I by the linear model compound and the enhanced sensing performance with an increment of porosity, this finding indicates that the porosity of IPF is important for the detection of I and an inducement of the sensing process. A fluorescent paper sensor was further developed, which shows high efficiency for the visual detection of I similar to the abovementioned sensor, suggesting its potential in convenient and on-site sensing of I. In addition, the paper sensor is recyclable with a remarkable fluorescence resuming ratio of 83% after 10 times cycle detection. Moreover, the developed sensor is used for the analysis of real samples. This work represents the first example of the detection of I by an ionic porous polymer. Compared with conventional iodide sensors, the present sensor does not require unique structures to form the pseudocavity during sensing I and can easily achieve high efficiency by incorporating ionic hydrogen bond donors into the porous network, indicating the importance of porosity and the feasibility of replacing the pseudocavity with a real cavity (or pore). More iodide sensors with high efficiency can be designed and fabricated by this novel and simple strategy.
通过简单的合成策略开发一种用于快速、灵敏且可视化检测碘离子（I⁻）的化学传感器仍然具有挑战性。在此，我们报道了一种高效的碘离子传感器，通过简单地将离子咪唑基团引入多孔网络中制备而成。该传感器，即荧光离子多孔框架（IPF），由八（（苄基氯）乙烯基）倍半硅氧烷与1,4 - 双（1 - 咪唑 - 1 - 基）苯的季铵化反应制备而成，具有中等孔隙率，Brunauer - Emmett - Teller表面积为379 m²/g，在紫外光激发下呈现蓝色荧光。IPF在水中的悬浮液能够在各种阴离子中高灵敏度、高选择性地检测I⁻，并通过荧光猝灭实现快速响应。与线性模型化合物对I⁻无响应以及随着孔隙率增加传感性能增强形成对比，这一发现表明IPF的孔隙率对于I⁻的检测以及传感过程的诱导至关重要。进一步开发了一种荧光纸传感器，其对I⁻的可视化检测效率与上述传感器相似，表明其在I⁻的便捷现场传感方面具有潜力。此外，该纸传感器可回收利用，在10次循环检测后荧光恢复率高达83%。此外，所开发的传感器用于实际样品的分析。这项工作代表了离子多孔聚合物检测I⁻的首个实例。与传统碘离子传感器相比，本传感器在检测I⁻时不需要独特的结构来形成假腔，并且通过将离子氢键供体纳入多孔网络可以轻松实现高效检测，这表明孔隙率的重要性以及用真实腔（或孔）替代假腔的可行性。通过这种新颖且简单的策略可以设计和制造出更多高效的碘离子传感器。
