• 关键词：电化学传感器  大气NO₂  环境监测  低成本

• 基金项目：国家自然科学基金（No.41530644，61275151）；国家自然科学基金重大研究计划培育项目（No.91544104）；安徽理工大学研究生创新基金项目（No.2017CX2035）

• 徐雨
• 安徽理工大学电气与信息工程学院, 淮南 232001

• 凌六一
• 1. 安徽理工大学电气与信息工程学院, 淮南 232001;2. 中国科学院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 合肥 230031

• 谢品华
• 1. 中国科学院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 合肥 230031;2. 中国科学技术大学环境科学与光电技术学院, 合肥 230026

• 胡仁志
• 中国科学院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 合肥 230031

• 李治艳
• 中国科学院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 合肥 230031

• 陈浩
• 中国科学院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 合肥 230031

• 摘要：为有序疏解大气NO₂监测环境日益复杂及成本高昂的光学探测仪器缺乏灵活性的困扰，研制了基于低成本电化学传感技术的测量系统，以四电极电化学传感器为NO₂浓度传感载体，基于差分算法补偿痕量浓度下零点电流漂移的干扰，实现了对大气NO₂的定量.结果表明，系统在摆脱有线数传束缚的基础上可稳定探测NO₂，对100 ppbv的NO₂标气响应时间T₉₀<34 s，标定探得其灵敏度为0.242 mV·ppbv^-1，时间分辨率为10 s时探测限为1.5 ppbv （3σ）.为验证准确性，将系统置于合肥西北郊科学岛进行了连续2个昼夜的大气NO₂测量，并与参考设备CRDS系统对比，探讨了测量结果，发现除去该系统因环境湿度贴近极限工作湿度时测量结果奇异部分，二者表现出良好的一致性，R²达到0.940，线性拟合斜率为1.047±0.006，接着分析了温湿度和其他痕量气体等干扰源.研究表明，本技术可为大气NO₂高分辨在线监测提供一种低成本便携途径.

• Abstract：In order to face the more and more complicated environment of atmospheric NO₂ measurement and make up the flexibility lack of the expensive optical instruments, low-cost electrochemical sensing technology for the quantification of NO₂ concentration was developed. In this method, a four-electrode electrochemical sensor was applied for NO₂ concentration detection and the interference of zero current drift was compensated by differential algorithm for trace concentration monitoring. Experimental results show that the NO₂ can be stably measured and data is transmitted by wireless technique, the response time (T₉₀) to 100 ppbv NO₂ is less than 34 s, the sensitivity of the system is 0.242 mV·ppbv^-1 and the detection limit is 1.5 ppbv (3σ) for NO₂ at a time resolution of 10 s. To verify the accuracy of the instrument, a field experiment was carried out in the northwestern suburb of Hefei city, the Hefei Science Island, for 2 consecutive days of atmospheric NO₂ measurements, and compared simultaneously with a CRDS instrument. Their comparison results show that the two instruments have a great agreement (R²=0.940) and have a fitting slope of 1.047±0.006 except for the singular data measured in an extreme humidity. Then, the interference sources, such as temperature, humidity and other trace gases, are analyzed, the results show that our electrochemical sensing technology is a low cost and portable means for the detection of atmospheric NO₂ with high resolution.

• Key words：electrochemical sensor  atmospheric NO₂  environmental measurement  low cost

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