Department of Chemistry, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Nov 22;9(46):40593-40603. doi: 10.1021/acsami.7b11317. Epub 2017 Nov 10.
Detection and control of air quality are major concerns in recent years for environmental monitoring and healthcare. In this work, we developed an integrated sensor architecture comprised of nanostructured composite sensing layers and a flexible heating substrate for portable and real-time detection of nitrogen dioxide (NO). As sensing layers, PdO-infiltrated CoO hollow nanocubes (PdO-CoO HNCs) were prepared by calcination of Pd-embedded Co-based metal-organic framework polyhedron particles. Single-walled carbon nanotubes (SWCNTs) were functionalized with PdO-CoO HNCs to control conductivity of sensing layers. As a flexible heating substrate, the Ni mesh electrode covered with a 40 nm thick Au layer (i.e., Ni(core)/Au(shell) mesh) was embedded in a colorless polyimide (cPI) film. As a result, SWCNT-functionalized PdO-CoO HNCs sensor exhibited improved NO detection property at 100 °C, with high sensitivity (S) of 44.11% at 20 ppm and a low detection limit of 1 ppm. The accelerated reaction and recovery kinetics toward NO of SWCNT-functionalized PdO-CoO HNCs were achieved by generating heat on the Ni(core)/Au(shell) mesh-embedded cPI substrate. The SWCNT-functionalized porous metal oxide sensing layers integrated on the mechanically stable Ni(core)/Au(shell) mesh heating substrate can be envisioned as an essential sensing platform for realization of low-temperature operation wearable chemical sensor.
近年来，空气质量的检测和控制是环境监测和医疗保健的主要关注点。在这项工作中，我们开发了一种集成传感器架构，由纳米结构复合传感层和柔性加热衬底组成，用于便携式和实时检测二氧化氮（NO）。作为传感层，通过煅烧嵌入钯的钴基金属有机骨架多面体颗粒制备了钯浸渍的氧化钴空心纳米立方体（PdO-CoO HNCs）。单壁碳纳米管（SWCNTs）用 PdO-CoO HNCs 功能化以控制传感层的导电性。作为柔性加热衬底，覆盖有 40nm 厚金层的镍网电极（即 Ni（芯）/Au（壳）网）嵌入无色聚酰亚胺（cPI）薄膜中。结果，SWCNT 功能化的 PdO-CoO HNCs 传感器在 100°C 下表现出改善的 NO 检测性能，在 20ppm 时灵敏度（S）为 44.11%，检测限低至 1ppm。通过在嵌入 cPI 基板的 Ni（芯）/Au（壳）网中产生热量，实现了 SWCNT 功能化的 PdO-CoO HNCs 对 NO 的加速反应和恢复动力学。机械稳定的 Ni（芯）/Au（壳）网加热衬底上集成的 SWCNT 功能化多孔金属氧化物传感层可以被视为实现低温操作可穿戴化学传感器的基本传感平台。
