Based on a naphthalene-threaded cucurbit[8]uril (CB[8]) rotaxane structure on a solid substrate, a new strategy for rapid, fully reversible, and highly sensitive detection of a broad class of explosives was developed by using one receptor. Due to the unique confinement effect and size exclusion of the CB[8] cavity, it is found that the intercalation of an explosive compound in the constructed rotaxane can significantly influence the photophysical property of the naphthalene core in the confined nanocavity of CB[8]. Dependent on the electronic structures and the sizes of explosive compounds, the fluorescence of the naphthalene core would be quenched or enhanced to different extents, leading to the direct detection and discrimination of distinctively different groups of trace explosives in the vapor phase, especially including the challenging aliphatic nitro-organics (RDX, HMX and PETN). Control experiments were performed to show the different sensing behaviors between the common organic vapors and nitrate-based explosives, which made it easy to realize the discrimination between target analytes and interferents. Due to the surface-attached sensing elements, a rapid response was also achieved in this system. Moreover, the non-covalent nature of the resulting heteroternary complex indicates that the trapped target molecules in the rotaxane structure are facilely removable by simply washing, demonstrating an excellent regeneration of the constructed explosive sensors for real-world application. The performed experiments suggested that the rotaxane structure-based sensing protocol opened a new way to develop a new kind of explosive sensors enabling a richer identification of threats.
基于固体基底上的
萘螺纹葫芦[8]
脲(CB[8])旋转烷结构,研究人员开发了一种新策略,利用一种受体对多种爆炸物进行快速、完全可逆和高灵敏度的检测。由于 CB[8] 腔具有独特的约束效应和尺寸排他性,研究发现,在所构建的旋转烷中夹杂爆炸性化合物会显著影响 CB[8] 约束纳米腔中
萘核的光物理特性。根据爆炸性化合物的电子结构和大小,
萘核的荧光会在不同程度上被淬灭或增强,从而直接检测和分辨气相中不同类别的痕量爆炸物,尤其是具有挑战性的脂肪族硝基有机物(RDX、HMX 和 PETN)。对照实验显示了普通有机蒸气和
硝酸盐类爆炸物之间不同的传感行为,从而轻松实现了目标分析物和干扰物之间的区分。由于采用了表面附着传感元件,该系统还实现了快速响应。此外,所产生的异三元复合物的非共价性质表明,轮烷结构中被捕获的目标分子只需简单清洗即可轻松去除,这表明所构建的爆炸物传感器在实际应用中具有极佳的再生性。实验结果表明,基于轮烷结构的传感协议为开发新型爆炸物传感器开辟了一条新途径,使其能够识别更多威胁。