Wan Hao, Yin Heyu, Mason Andrew J
Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan, 48824, USA.
Sens Actuators B Chem. 2017 Apr;242:658-666. doi: 10.1016/j.snb.2016.11.103.
Intense study on gas sensors has been conducted to implement fast gas sensing with high sensitivity, reliability and long lifetime. This paper presents a rapid amperometric method for gas sensing based on a room temperature ionic liquid electrochemical gas sensor. To implement a miniaturized sensor with a fast response time, a three electrode system with gold interdigitated electrodes was fabricated by photolithography on a porous polytetrafluoroethylene substrate that greatly enhances gas diffusion. Furthermore, based on the reversible reaction of oxygen, a new transient double potential amperometry (DPA) was explored for electrochemical analysis to decrease the measurement time and reverse reaction by-products that could cause current drift. Parameters in transient DPA including oxidation potential, oxidation period, reduction period and sample point were investigated to study their influence on the performance of the sensor. Oxygen measurement could be accomplished in 4 s, and the sensor presented a sensitivity of 0.2863 μA/[%O] and a linearity of 0.9943 when tested in air samples with different oxygen concentrations. Repeatability and long-term stability were also investigated, and the sensor was shown to exhibit good reliability. In comparison to conventional constant potential amperometry, transient DPA was shown to reduce relative standard deviation by 63.2%. With transient DPA, the sensitivity, linearity, repeatability, measurement time and current drift characteristics demonstrated by the presented gas sensor are promising for acute exposure applications.
为实现具有高灵敏度、可靠性和长寿命的快速气体传感，人们对气体传感器进行了深入研究。本文提出了一种基于室温离子液体电化学气体传感器的快速安培法气体传感技术。为实现具有快速响应时间的小型化传感器，通过光刻技术在多孔聚四氟乙烯基板上制作了带有金叉指电极的三电极系统，该基板极大地增强了气体扩散。此外，基于氧的可逆反应，探索了一种新的瞬态双电位安培法（DPA）用于电化学分析，以减少测量时间和可能导致电流漂移的逆反应副产物。研究了瞬态DPA中的氧化电位、氧化时间、还原时间和采样点等参数对传感器性能的影响。在不同氧气浓度的空气样品中测试时，氧气测量可在4秒内完成，该传感器的灵敏度为0.2863 μA/[%O]，线性度为0.9943。还研究了重复性和长期稳定性，结果表明该传感器具有良好的可靠性。与传统的恒电位安培法相比，瞬态DPA的相对标准偏差降低了63.2%。所展示的气体传感器通过瞬态DPA所表现出的灵敏度、线性度、重复性、测量时间和电流漂移特性，在急性暴露应用中具有广阔前景。
