微电流法直接检测非电活性气体二氧化碳

基于非电活性气体CO_2在‘二甲亚砜/铂微电极’体系中定量的电还原反应,提出微电流法常温直接检测二氧化碳.在常规气敏微电极和硅一体化薄膜微电极器件上获得了满意的气敏响应特性:好的线性响应关系、灵敏度和响应速度.用硅微机械加工技术批量构制的薄膜微电极器件,既保持了微电极的全部优点,又实现了微电流器件结构的一体化,电流响应异常稳定和重现.

Direct Detection of Electro-inactive Gas Carbon Dioxide by Microamperometry

Based on the quantitative electroreduction of carbon dioxide at the Pt microelec-trode surface that is in contact with the non-aqueous electrolyte (DMSO), a microelec-trochemical amperometric method for the direct detection of electro-inactive gas CO2 at room temperature was presented. The satisfactory CO2 gas-sensing characteristics, such as good linearity of the calibration curve over the entire CO2 concentration range, 90% response time of 25-30 s, detection limits of 0. 4-0. 5% CO2 in N2, and relatively high sensitivity, were obtained using a gas-sensing microelectrode and a thin-film microelectrode device, respectively. For comparison, the microfabricated silicon integrated thin-film microelectrode devices exhibited all the advantages of microelectrodes in the field of electroanalysis, and furthermore, silicon micromachining techniques provided a geometrically well-defined, highly uniform thin-film microelectrode, at which current response was excellent in stability and re-producibility.