One striking feature of molecular rotors is their ability to change conformation with detectable optical signals through molecular motion when stimulated. However, due to the strong intermolecular interactions, synthetic molecular rotors have often relied on fluid environments. Here, we take advantage of the solid-state intramolecular motion of aggregation-induced emission (AIE) molecular rotors and one-dimensional fibers, developing highly sensitive optical fiber sensors that respond to ambient humidity rapidly and reversibly with observable chromatic fluorescence change. Moisture environments induce the swelling of the polymer fibers, activating intramolecular motions of AIE molecules to result in red-shifted fluorescence and linear response to ambient humidity. In this case, polymer fiber provides a process-friendly architecture and a physically tunable medium for the embedded AIE molecules to manipulate their fluorescence response characteristics. Assembly of sensor fibers could be built into hierarchical structures, which are adaptive to diverse-configuration for spatial-temporal humidity mapping, and suitable for device integration to build light-emitting sensors as well as touchless positioning interface for intelligence systems.

中文翻译：

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用于荧光传感器的由环境湿度驱动的连续纤维中的固态分子内运动

分子转子的一个显着特征是它们能够在受到刺激时通过分子运动改变具有可检测光信号的构象。然而，由于分子间的强相互作用，合成分子转子经常依赖于流体环境。在这里，我们利用聚集诱导发射 (AIE) 分子转子和一维纤维的固态分子内运动，开发了高灵敏度光纤传感器，可快速、可逆地响应环境湿度，并具有可观察的彩色荧光变化。潮湿环境会导致聚合物纤维膨胀，激活 AIE 分子的分子内运动，从而导致荧光红移和对环境湿度的线性响应。在这种情况下，聚合物纤维为嵌入的 AIE 分子提供了一种工艺友好的架构和物理可调介质，以操纵它们的荧光响应特性。传感器光纤的组装可以构建成层次结构，适应时空湿度映射的不同配置，适合设备集成以构建发光传感器以及智能系统的非接触式定位界面。