School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, P. R. China.
Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province, Hangzhou, 310058, P. R. China.
Adv Sci (Weinh). 2024 Jul;11(25):e2400207. doi: 10.1002/advs.202400207. Epub 2024 Apr 24.
Wearable sensors hold immense potential for real-time and non-destructive sensing of volatile organic compounds (VOCs), requiring both efficient sensing performance and robust mechanical properties. However, conventional colorimetric sensor arrays, acting as artificial olfactory systems for highly selective VOC profiling, often fail to meet these requirements simultaneously. Here, a high-performance wearable sensor array for VOC visual detection is proposed by extrusion printing of hybrid inks containing surface-functionalized sensing materials. Surface-modified hydrophobic polydimethylsiloxane (PDMS) improves the humidity resistance and VOC sensitivity of PDMS-coated dye/metal-organic frameworks (MOFs) composites. It also enhances their dispersion within liquid PDMS matrix, thereby promoting the hybrid liquid as high-quality extrusion-printing inks. The inks enable direct and precise printing on diverse substrates, forming a uniform and high particle-loading (70 wt%) film. The printed film on a flexible PDMS substrate demonstrates satisfactory flexibility and stretchability while retaining excellent sensing performance from dye/MOFs@PDMS particles. Further, the printed sensor array exhibits enhanced sensitivity to sub-ppm VOC levels, remarkable resistance to high relative humidity (RH) of 90%, and the differentiation ability for eight distinct VOCs. Finally, the wearable sensor proves practical by in situ monitoring of wheat scab-related VOC biomarkers. This study presents a versatile strategy for designing effective wearable gas sensors with widespread applications.
可穿戴传感器在实时、非破坏性的挥发性有机化合物 (VOC) 传感方面具有巨大潜力，这需要高效的传感性能和稳健的机械性能。然而，传统的比色传感器阵列作为高度选择性 VOC 分析的人工嗅觉系统，往往无法同时满足这些要求。在这里，通过含有表面功能化传感材料的混合油墨的挤出印刷，提出了一种用于 VOC 视觉检测的高性能可穿戴传感器阵列。经过表面修饰的疏水性聚二甲基硅氧烷 (PDMS) 提高了 PDMS 涂层染料/金属有机骨架 (MOFs) 复合材料的耐湿性和 VOC 敏感性。它还增强了它们在液态 PDMS 基质中的分散性，从而促进了混合液体成为高质量的挤出印刷油墨。这些油墨可以直接精确地印刷在各种基底上，形成均匀且高颗粒负载（70wt%）的薄膜。印刷在柔性 PDMS 基底上的薄膜具有良好的柔韧性和拉伸性，同时保留了染料/MOFs@PDMS 颗粒的优异传感性能。此外，印刷传感器阵列对亚 ppm 级别的 VOC 水平表现出更高的灵敏度，对 90%的高相对湿度 (RH) 具有显著的抗干扰能力，并且能够区分八种不同的 VOC。最后，可穿戴传感器通过原位监测小麦赤霉病相关 VOC 生物标志物证明了其实用性。本研究提出了一种设计有效可穿戴气体传感器的通用策略，具有广泛的应用前景。
