1成果简介
　　本文，山东理工大学尹广超、郑州大学卢思宇教授等在《ADVANCED MATERIALS》期刊发表名为“Polyurethane Nonwovens Integrated with Nanocomposite as Twist-Assisted Healing Flexible Sensor for Ultrasensitive Room-Temperature NO2 Detection”的论文，研究通过将还原氧化石墨烯（rGO）作为导电介质依次引入聚氨酯（PU）无纺布，再以金/钯纳米颗粒（Au/Pd NPs）和聚噻吩（PEDOT）复合材料作为核心传感层进行修饰，成功开发出一种扭转辅助自愈合柔性传感器，可在室温下实现对二氧化氮（NO₂）的超灵敏选择性检测。优化后的Au/Pd&PEDOT@rGO@PU传感器在宽NO₂浓度范围（0.1–800 ppm）内展现卓越性能：灵敏度显著提升（约27%/1 ppm）、响应/恢复速率迅捷（7s/38s）、检测限达超低水平（2 ppb），并在28℃条件下保持优异选择性。
　　这种卓越的NO₂传感性能源于协同效应：外层PEDOT涂层暴露大量传感位点，Au/Pd纳米粒子发挥优异催化作用，而rGO骨架则加速电荷转移。更重要的是，该传感器展现出卓越的机械性能，包括良好的坚固性、扭转辅助自愈能力和优异的防水性。凭借可扩展的制备工艺、简易的结构设计和具有竞争力的检测指标，这种柔性传感器为实际NO₂监测应用提供了极具前景的平台。
　　2图文导读 

　　图1、Synthesis and characterization. a) Schematic synthesis of Au/Pd&PEDOT@rGO@PU. b–d) Optical microscope image of b) PU, c) rGO@PU, and d) Au/Pd&PEDOT@rGO@PU. e–h) Nanostructure details of Au/Pd&PEDOT@rGO@PU: e) TEM image, f) High-resolution TEM images and the lattice distance of various crystal planes inset. g) High-angle annular dark field (HAADF)-STEM image, h) the overall EDS elements mapping and h1–h6) the individual element mapping of C, N, O, S, Pd, Au, respectively. i) XRD patterns of PU, rGO@PU, Au&PEDOT@rGO@PU, Pd&PEDOT@rGO@PU and Au/Pd&PEDOT@rGO@PU. j) The Raman spectra of GO, rGO, Au/Pd&PEDOT, and Au/Pd&PEDOT@rGO. k) The high-resolution XPS spectra of S2p of Au&PEDOT@rGO@PU, Pd&PEDOT@rGO@PU, and Au/Pd&PEDOT@rGO@PU.

　　图2、The gas sensing performance of sensors at room temperature (28 °C). a) Resistance response-recovery curve and b) response plots of rGO@PU, Au&PEDOT@rGO@PU, Pd&PEDOT@rGO@PU, and various Au/Pd&PEDOT@rGO@PU sensors toward 0.1–800 ppm NO2. c) Response/ recovery time of rGO@PU, Au &PEDOT@rGO@PU, Pd&PEDOT@rGO@PU and Au/Pd&PEDOT@rGO@PU sensors. d) The response of Au/Pd&PEDOT@rGO@PU (1:1) sensor to 1 ppm NO2 and 10 ppm other gases. e) The response of Au/Pd&PEDOT@rGO@PU (1:1) sensor to 2–100 ppb NO2. f) The response of the Au/Pd&PEDOT@rGO@PU (1:1) sensor toward 1 ppm NO2 under varied ambient humidity (15–85% RH). g) Device-to-device reproducibility and the cyclic stability of five independent Au/Pd&PEDOT@rGO@PU (1:1) sensors to 1 ppm NO2.

　　图3、The gas-sensing mechanism of Au/Pd&PEDOT@rGO for detecting NO2 at room temperature. a) The schematic illustration, b) the energy band diagram, and c) the interaction energy with various gases, respectively.

　　图4、Evaluation of flexibility and twist-assisted healing performance. a) The photos of lightweight and tailorable sensors. b) The stretching and twist-healing process of the sensor. c) The response of Au/Pd&PEDOT@rGO@PU sensor to 1 ppm NO2 via stretching 0–225%. d) The normalized response curves to 1 ppm NO2 of the pristine sensor, the twist-healing sensor device (after fracture), and the simple overlapping sensor device (after fracture). e,f) The response of Au/Pd&PEDOT@rGO@PU sensor to 1 ppm NO2 e) under various bending angles, and f) under loading 0–50 g weight, respectively.

　　图5、Application demonstration. a) Flexible Au/Pd&PEDOT@rGO@PU sensors integrated in gloves, medical masks, and clothing. b) Simulated detection of Au/Pd&PEDOT@rGO@PU sensor to toxic gases. c) The sensing stability to 1 ppm NO2 before and after being immersed in water.
　　3小结
　　综上所述，通过将Au/Pd&PEDOT@rGO复合材料集成到商用聚氨酯无纺布上，成功开发出一种扭转辅助自愈型柔性传感器，可在室温下实现选择性NO₂检测。优化后的传感器展现出卓越的NO₂传感性能，这归功于三种关键组分的协同效应：PEDOT外层涂层提供丰富的活性传感位点，催化性Au/Pd纳米颗粒增强气体相互作用，而rGO骨架则促进高效电荷转移。该独特结构实现了对低浓度NO₂的稳定选择性检测，室温下检测限达2 ppb的超低水平。理论Eint计算结果证实了其对NO₂相对于干扰气体的选择性。柔性PU纤维基底赋予传感器卓越的机械韧性，兼具可折叠性、可定制性、可扭转性及优异防水性。令人瞩目的是，该传感器展现出独特的扭转自愈能力：断裂段可通过扭转过程有效重组，同时保持传感功能。总体而言，本研究开发的柔性传感器在智能环境NO₂监测和工业NO₂泄漏报警领域具有广阔应用前景。
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