Single-layer assembly of pyrene end-capped terthiophene and its sensing performances to nitroaromatic explosives
Single-layer assembly of pyrene end-capped terthiophene and its sensing performances to nitroaromatic explosives
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芘封端三噻吩的单层组装及其对硝基芳烃炸药的传感性能
DOI：
10.1039/c1jm14022a
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发表时间：
2012-01-01
影响因子：
--
通讯作者：
Fang, Yu
中科院分区：
文献类型：
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作者：
Liu, Taihong;Ding, Liping;Fang, Yu
合成了 5-(1-芘基)-2,2':5',2''-三联噻吩 (Py-3T) 的三联噻吩 (3T) 衍生物，并采用单层化学技术通过柔性间隔物化学固定到玻璃晶片表面。与以相同方式制造但以 3T 作为荧光团的薄膜不同，本研究中制造的薄膜在环境条件下具有前所未有的光化学稳定性。荧光研究表明，所制造的薄膜的发射会因硝基芳香族化合物（NAC）的存在而被显着且选择性地猝灭，硝基芳香族化合物是一组典型的爆炸物，无论是在气相还是在水溶液中。实验和理论研究表明，猝灭可能是电子从富电子 Py-3T 转移到缺电子 NAC 的结果。研究发现，对于气相传感，系统的响应时间和淬火效率主要由测试的 NAC 的蒸气压决定。还研究了该薄膜对水相中 NAC 的传感性能。然而，在这种情况下，薄膜与苦味酸（PA）（一种典型的 NAC）的特异性结合使得该化合物表现出比其他 NAC 更优异的猝灭效率。而且响应速度快，90秒内达到平衡。此外，酸、碱、苹果汁、香料和常见的有机溶剂等对水相中的传感影响很小。气相传感和水溶液传感都是可逆的。此外，如果妥善保存，胶片可稳定保存至少 6 个月。本工作的基本贡献不仅是创造了一种对气相中的NAC，特别是水相中的PA具有优异传感性能的新型荧光薄膜，而且还提供了一种新的光化学稳定的荧光团，它可以结合小分子荧光团和共轭聚合物/低聚物的优点，用于开发新型荧光传感薄膜。
A terthiophene (3T) derivative of 5-(1-pyrenyl)-2,2':5',2 ''-terthiophene (Py-3T) was synthesized and chemically immobilized onto a glass wafer surface via a flexible spacer by employing a single-layer chemistry technique. Unlike the film fabricated in the same way but with 3T as the fluorophore, the film fabricated in the present study possesses unprecedented photochemical stability at ambient conditions. Fluorescence studies revealed that the emission of the film as fabricated is significantly and selectively quenched by the presence of nitroaromatic compounds (NACs), a group of typical explosives, both in the vapor phase and in aqueous solution. Experimental and theoretical studies demonstrated that the quenching may be a result of electron transfer from the electron-rich Py-3T to the electron-deficient NACs. It was found that for vapor phase sensing, the response time and the quenching efficiency of the systems are dominantly determined by the vapor pressures of the NACs tested. The sensing performances of the film to NACs in aqueous phase were also investigated. In this case, however, the specific binding of the film to picric acid (PA), a typical NAC, makes the compound show a superior quenching efficiency than other NACs. Moreover, the response is fast and reaches equilibrium within 90 s. Furthermore, acids, bases, apple juice, perfume, and commonly found organic solvents etc. show little effect upon the sensing in aqueous phase. Both the vapor phase sensing and the aqueous solution sensing are reversible. Furthermore, the film is stable for at least 6 months provided it is properly preserved. The basic contribution of the present work is not only creating a new fluorescent film of superior sensing properties to NACs in the vapor phase, in particular to PA in the aqueous phase, but also providing a new photochemically stable fluorophore, which may combine the advantages of small molecular fluorophores and those of conjugated polymers/oligomers, for developing new fluorescent sensing films.