ACS Sensors
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2023
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IF 8.9
Shiyuan Xu,Xuemei Liu,Jiaying Wu,Jianmin Wu
The detection of nitric oxide in human exhaled breath (EB) has received wide attention due to its close relationship with respiratory tract inflammation. Herein, a ppb-level NOx chemiresistive sensor was prepared by assembling graphene oxide (GO) with a conductive π–d conjugated metal–organic framework Co3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) in the presence of poly(dimethyldiallylammonium chloride) (PDDA). The construction of a gas sensor chip was achieved by drop-casting the GO/PDDA/Co3(HITP)2 composite onto ITO-PET interdigital electrodes, followed by in situ reduction of GO to reduced graphene oxide (rGO) in hydrazine hydrate vapor. Compared with bare rGO, the nanocomposite shows significantly improved sensitivity and selectivity for NOx among various gas analytes owing to its folded and porous structure as well as its numerous active sites. The limit of detection (LOD) for NO and NO2 can reach as low as 11.2 and 6.8 ppb, respectively, and the response/recovery time to 200 ppb NO is 24/41 s. These results indicate that rGO/PDDA/Co3(HITP)2 can achieve a sensitive and fast response toward NOx at room temperature (RT). Additionally, good repeatability and long-term stability were observed. Furthermore, the sensor shows improved humidity tolerance owing to the presence of hydrophobic benzene rings in Co3(HITP)2. To demonstrate its ability in EB detection, EB samples collected from healthy individuals were spiked with a certain amount of NO to simulate the EB of respiratory inflammatory patients. The sensor can successfully distinguish healthy people from the simulated patients. Furthermore, in real clinical sample detection, the sensor can further differentiate acute respiratory inflammatory patients from the chronic ones.
研究领域:
材料科学
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医学诊断
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传感技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sensors
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2025
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IF 9.1
Weirong Zhou,Guoxuan Gu,Yuan Gao,Jiayin Han,Ning Yu,Chao Liao,Geyu Lu
Monitoring trace levels of nitrogen oxides (NOx) in high-humidity agricultural greenhouse environments is essential for both crop growth and workers’ health. However, achieving reliable NOx detection under extreme humidity remains challenging. Herein, this work presents an ultralow-detection-limit and highly humidity-tolerant NOx sensor based on Ag2Te/CeO2 nanocomposites. To the best of our knowledge, this is the first demonstration of Ag2Te/CeO2 heterostructures for gas sensing. Among the as-prepared samples, the optimal Ag2Te/CeO2 sample, with a molar ratio of 1:2, exhibited superior response and an ultralow detection limit of 5 ppb NO2 at 65 °C. The sensor response retained over 92% of its regular response even at 99% relative humidity. Density functional theory (DFT) calculations suggest that minimal H2O adsorption on Ag2Te and strong NO2 adsorption on CeO2, along with the formation of an n–n heterojunction, synergistically enhanced performance. Moreover, the sensor was further integrated into an Internet of Plants (IoP) environmental monitoring system. This work provides a new strategy for designing humidity-tolerant NOx sensors and offers a core device for smart agriculture.
研究领域:
材料科学
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环境科学
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农业技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2025
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IF 19
Dongli Li,Yinan Dong,Hua Zhang,Dagang Liu,Zhituo Geng,Chenxi Li,Hao Li,Jiayao Zhou,Zhipeng Li,Hai Lin,Weitian Zhang,Shengze Yu,Shuyan Yu,Congju Li,Yongping Huang,Jingkun Jiang,Zehui Li
Nitrogen oxides (NO x ) monitoring requires sensor platforms that deliver ppb-level sensitivity, ambient-temperature operation, and molecular discrimination. However, rapid and selective NO x detection at room temperature remains elusive. Although 2D transition metal carbides/nitrides (MXenes) show promise in chemiresistive sensing, their susceptibility to ambient degradation and poor selectivity limit practical deployment. Here, a room-temperature NO x sensor is developed by epitaxially growing Hofmann-type metal–organic frameworks (Ni-pyz) on oxygen-terminated monolayer large-size MXene (Ti 3 C 2 T x ). The Ni-pyz/Ti 3 C 2 T x heterostructure exhibits enhanced sensitivity (4.8 and 5.5 times compared to Ti 3 C 2 T x ) and low detection limits (8.8 and 6.9 ppb) for NO and NO 2 , along with high selectivity and good stability (>85% response after 8 weeks). The enhanced sensitivity results from electronic coupling between the Ti 3 C 2 T x and Ni(CN) 4 , promoting charge transfer with NO x . The improved selectivity arises from the pore confinement effect of Ni-pyz and the specific adsorption of NO x through Lewis acid-base interactions with open Ni sites. Importantly, the dynamic response of Ni-pyz/Ti 3 C 2 T x closely mirrors that of a trace-level chemiluminescence NO x analyzer at low NO x concentrations, enabling high-temporal-resolution, long-term atmospheric monitoring. This functional strategy overcomes the insufficiency of MXene-based gas sensors, paving the way for the development of high-performance sensors.
研究领域:
材料科学
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纳米技术
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化学传感
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环境监测
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金属有机框架（MOFs）
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）