Highly Sensitive Capacitive Gas Sensing at Ionic Liquid-Electrode Interfaces

作者：Wang Zhe; Guo Min; Mu Xiaoyi; Sen Soumyo; Insley Thomas; Mason Andrew J; Kral Petr; Zeng Xiangqun^*

来源：Analytical Chemistry, 2016, 88(3): 1959-1964.

DOI：10.1021/acs.analchem.5b04677

We have developed an ultrasensitive gas detection method based on the measurement of a differential capacitance of electrified ionic liquid (IL) electrode interfaces in the presence and absence of adsorbed gas molecules. The observed change of differential capacitance has a local maximum at a certain potential that is unique for each type of gas, and its amplitude is related to the concentration of the gas molecules. We establish and validate this gas-sensing method by characterizing SO2 detection at ppb levels with less than 1.8% signal from other interfering species (i.e., CO2, O-2, NO2, NO, SO2, H2O, H-2 and cyclohexane, tested at the same concentration as SO2). This study opens a new avenue of utilizing tunable electrified IL electrode interfaces for selective sensing of molecules with a kinetic size resolution of 0.1 angstrom.

• 出版日期2016-2-2