Response Surface Modeling of the Steady-State Impedance Responses of Gas Sensor Arrays Comprising Functionalized Carbon Nanotubes to Detect Ozone and Nitrogen Dioxide.
Response Surface Modeling of the Steady-State Impedance Responses of Gas Sensor Arrays Comprising Functionalized Carbon Nanotubes to Detect Ozone and Nitrogen Dioxide.
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DOI：
10.3390/s23208447
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发表时间：
2023-10-13
期刊：
影响因子：
--
通讯作者：
Bekyarova E
中科院分区：
文献类型：
--
作者：
Naishadham K;Naishadham G;Cabrera N;Bekyarova E
碳纳米管（CNT）传感器为臭氧（O3）和二氧化氮（NO2）的环境监测提供了一个通用的化学平台，这两种重要的空气污染物已知会导致急性呼吸和心血管健康问题。由于其独特的性能，包括高的表面体积比、众多的活性位点和具有高表面反应性的晶面，以及高的导热性和导电性，CNTs已显示出作为传感层的巨大潜力。纳米技术具有紧凑、低功耗和易于与电子设备集成等操作优势，预计将对便携式低成本环境传感器产生重大影响。通过聚合物、金属和金属氧化物功能化碳纳米管可以提高灵敏度。本文研究了一种由有机官能团共价修饰的单壁碳纳米管组成的O3和NO2传感器双元阵列的设计和性能。与传统的化学电阻不同，我们通过测量交流阻抗的幅度和相位来表征传感器阵列的响应。多元响应为传感器阵列数据处理提供了更高的自由度。每个传感器的复杂阻抗在控制气流室中以5 kHz测量，使用60-120 ppb范围内的O3和20 - 80 ppb范围内的NO2混合气体。测量数据显示，O3传感器的响应变化范围为26-36%，NO2传感器的响应变化范围为5-31%。采用多变量优化方法拟合实验室测量结果与响应面数学模型，计算灵敏度和选择性。臭氧传感器具有高灵敏度（例如，阻抗大小为5至6 MΩ/ppb）和高选择性（0.8至0.9），用于低于30 ppb的干扰（NO2）水平。然而，二氧化氮传感器是没有选择性的。
Carbon nanotube (CNT) sensors provide a versatile chemical platform for ambient monitoring of ozone (O3) and nitrogen dioxide (NO2), two important airborne pollutants known to cause acute respiratory and cardiovascular health problems. CNTs have shown great potential for use as sensing layers due to their unique properties, including high surface to volume ratio, numerous active sites and crystal facets with high surface reactivity, and high thermal and electrical conductivity. With operational advantages such as compactness, low-power operation, and easy integration with electronics devices, nanotechnology is expected to have a significant impact on portable low-cost environmental sensors. Enhanced sensitivity is feasible by functionalizing the CNTs with polymers, metals, and metal oxides. This paper focuses on the design and performance of a two-element array of O3 and NO2 sensors comprising single-walled CNTs functionalized by covalent modification with organic functional groups. Unlike the conventional chemiresistor in which the change in DC resistance across the sensor terminals is measured, we characterize the sensor array response by measuring both the magnitude and phase of the AC impedance. Multivariate response provides higher degrees of freedom in sensor array data processing. The complex impedance of each sensor is measured at 5 kHz in a controlled gas-flow chamber using gas mixtures with O3 in the 60–120 ppb range and NO2 between 20 and 80 ppb. The measured data reveal response change in the 26–36% range for the O3 sensor and 5–31% for the NO2 sensor. Multivariate optimization is used to fit the laboratory measurements to a response surface mathematical model, from which sensitivity and selectivity are calculated. The ozone sensor exhibits high sensitivity (e.g., 5 to 6 MΩ/ppb for the impedance magnitude) and high selectivity (0.8 to 0.9) for interferent (NO2) levels below 30 ppb. However, the NO2 sensor is not selective.
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影响因子：
3.3
作者：
Bekyarova, E;Davis, M;Haddon, RC
通讯作者：
Haddon, RC
DOI：
10.3390/s140406806
发表时间：
2014-04-14
期刊：
Sensors (Basel, Switzerland)
影响因子：
--
作者：
Colindres SC;Aguir K;Cervantes Sodi F;Vargas LV;Salazar JM;Febles VG
通讯作者：
Febles VG
DOI：
10.1080/02786826.2014.912745
发表时间：
2014-05-19
期刊：
Aerosol science and technology : the journal of the American Association for Aerosol Research
影响因子：
--
作者：
通讯作者：
--
影响因子：
4
作者：
Chopra, S;Pham, A;Rao, AM
通讯作者：
Rao, AM
DOI：
10.3390/s23073465
发表时间：
2023-03-26
期刊：
Sensors (Basel, Switzerland)
影响因子：
--
作者：
Nguyen VC;Cha HY;Kim H
通讯作者：
Kim H