Smart Ionic Liquids-based Gas Sensors
Ionic liquids are “designer-solvents” that are promising candidates for substituting conventional aqueous/organic solvents in gas sensors. This is due to their unique set of properties, such as high ionic conductivity, great chemical and thermal stability, and low vapour pressure. The latter property is important in order to fabricate a membrane-free gas sensor. Direct contact between the gas analytes and the electrolyte medium (solvent) is preferable in order to enhance the overall performance (response time and sensitivity) of the gas sensor. Recent surges in publications, reports, and books have suggested increasing research interests towards this class of “smart” solvents. This chapter summarises the recent developments in ionic liquids-based gas sensor designs, for example electrochemical, optical, and mass-based. The performance of each gas sensor design to detect specific gas analyte was compared in terms of their sensitivity, response time, and limit of detection.