Ionic Liquid-Packed Microfluidic Device with Non-Planar Microelectrode as a Miniaturized Electrochemical Gas Sensor
Document Type
Article
Publication Date
1-1-2023
Abstract
Integrating transducer/sensing materials into microfluidic platforms has enhanced gas sensors′ sensitivity, selectivity, and response time while facilitating miniaturization. In this manuscript, microfluidics has been integrated with non-planar microelectrode array and functionalized ionic liquids (ILs) to develop a novel miniaturized electrochemical gas sensor architecture. The sensor employs the IL 1-ethyl-3-methylimidazolium 2-cyanopyrolide ([EMIM][2-CNpyr]) as the electrolyte and capture molecule for detecting carbon dioxide (CO2). The three-layer architecture of the sensor consists of a microchannel with the IL sandwiched between glass slides containing microelectrode arrays, forming a non-planar structure. This design facilitates electric field penetration through the IL, capturing CO2 binding perturbations throughout the channel volume to enhance sensitivity. CO2 binding with [EMIM][2-CNpyr] generates carboxylate ([EMIM]+-CO2−]), carbamate ([2-CNpyr]-CO2−]), and pyrrole-2-carbonitrile (2-CNpyrH) species, significantly decreasing the conductivity. The viscosity is also increased, leading to a further decrease in conductivity. These cumulative effects increase charge transfer resistance in the impedance spectrum, allowing a linear calibration curve obtained using Langmuir Isotherm. The sensitivity and reproducibility in CO2 detection are demonstrated by two electrode configurations using the calibration curve. The developed sensor offers a versatile platform for future applications.
Identifier
85168516046 (Scopus)
Publication Title
Journal of the Electrochemical Society
External Full Text Location
https://doi.org/10.1149/1945-7111/aced6e
e-ISSN
19457111
ISSN
00134651
Issue
8
Volume
170
Grant
2048361
Fund Ref
National Science Foundation
Recommended Citation
Kaaliveetil, Sreerag; Lee, Yun Yang; Li, Zhenglong; Cheng, Yu Hsuan; Menon, Niranjan Haridas; Dongare, Saudagar; Gurkan, Burcu; and Basuray, Sagnik, "Ionic Liquid-Packed Microfluidic Device with Non-Planar Microelectrode as a Miniaturized Electrochemical Gas Sensor" (2023). Faculty Publications. 2224.
https://digitalcommons.njit.edu/fac_pubs/2224
