High performance aniline vapor detection based on multi-branched fluorescent triphenylamine-benzothiadiazole derivatives: branch effect and aggregation control of the sensing performance
作者:Liqi Shi、Chao He、Defeng Zhu、Qingguo He、Yang Li、Yan Chen、Yuxi Sun、Yanyan Fu、Dan Wen、Huimin Cao、Jiangong Cheng
DOI:10.1039/c2jm30933e
日期:——
A series of benzothiadiazole-pyridine branched triphenylamine derivatives TPA1BP, TPA2BP and TPA3BP have been designed and synthesized to sense aniline vapor with distinguished sensitivity, selectivity and repeatability via photoinduced electron transfer (PET). Suitable energy levels ensure the high selectivity to aniline for all three sensory materials. However, the aggregations of the three materials in the film state on a quartz substrate increase along with the branches, which highly deteriorate the sensing performance for less efficient fluorescence, lower contact area and inferior vapor penetration. The oriented ZnO nanorod array is introduced as the substrate to eliminate the aggregation and enhance the sensing performance, because of its high surface-to-volume ratio and 3D structure. Therefore, the cooperative effect that the sensing performance of TPAnBP increases with the number of branches could be observed; fluorescence intensities of the films on the nano-substrate are 34%, 45% and 54% quenched for TPA1BP, TPA2BP and TPA3BP, respectively, after exposure to 300 ppm aniline vapor for less than 5 s. Moreover, the fluorescences of all three sensory materials are almost 100% recovered by eluting with fresh air for 20 s and could be reused immediately. The detection limits are predicted to be 1 ppm for TPA1BP, 100 ppb for TPA2BP and 1 ppb for TPA3BP according to the fitted plot, demonstrating a significant cooperative effect of the molecular branches.
我们设计并合成了一系列苯并噻二唑吡啶支链三苯胺衍生物 TPA1BP、TPA2BP 和 TPA3BP,它们通过光诱导电子转移(PET)感应苯胺蒸汽,具有出色的灵敏度、选择性和可重复性。合适的能级确保了这三种感光材料对苯胺的高选择性。然而,这三种材料在石英基底上的薄膜状态下的聚集会随着分支的增加而增加,从而大大降低了传感性能,如荧光效率低、接触面积小和蒸汽穿透性差。由于定向氧化锌纳米棒阵列具有高表面体积比和三维结构,因此将其作为基底可以消除聚集现象并提高传感性能。因此,可以观察到 TPAnBP 的传感性能随分支数量的增加而增加的协同效应;纳米基底上的薄膜在暴露于 300 ppm 苯胺蒸气中不到 5 秒钟后,TPA1BP、TPA2BP 和 TPA3BP 的荧光强度分别淬灭了 34%、45% 和 54%。根据拟合曲线,预计 TPA1BP 的检测限为 1 ppm,TPA2BP 为 100 ppb,TPA3BP 为 1 ppb,这表明分子分支具有显著的协同效应。