title: Microcontact Printing of Thiol-Functionalized Ionic Liquid Microarrays for "Membrane-less" and "Spill-less" Gas Sensors.
abstract: Lab-on-a-chip systems have gained significant interest for both chemical synthesis and assays at the micro-to-nanoscale with a unique set of benefits. However, solvent volatility represents one of the major hurdles to the reliability and reproducibility of the lab-on-a-chip devices for large-scale applications. Here we demonstrate a strategy of combining nonvolatile and functionalized ionic liquids with microcontact printing for fabrication of "wall-less" microreactors and microfluidics with high reproducibility and high throughput. A range of thiol-functionalized ionic liquids have been synthesized and used as inks for microcontact printing of ionic liquid microdroplet arrays onto gold chips. The covalent bonds formed between the thiol-functionalized ionic liquids and the gold substrate offer enhanced stability of the ionic liquid microdroplets, compared to conventional nonfunctionalized ionic liquids, and these microdroplets remain stable in a range of nonpolar and polar solvents, including water. We further demonstrate the use of these open ionic liquid microarrays for fabrication of "membrane-less" and "spill-less" gas sensors with enhanced reproducibility and robustness. Ionic-liquid-based microarray and microfluidics fabricated using the described microcontact printing may provide a versatile platform for a diverse number of applications at scale.
authors: School of Chemistry, UNSW Australia , Sydney, NSW 2052, Australia.
authors: Richard
authors: R
authors: Gondosiswanto
authors: School of Chemistry, UNSW Australia , Sydney, NSW 2052, Australia.
authors: Christian A
authors: CA
authors: Gunawan
authors: School of Chemistry, UNSW Australia , Sydney, NSW 2052, Australia.
authors: David B
authors: DB
authors: Hibbert
authors: School of Chemistry, UNSW Australia , Sydney, NSW 2052, Australia.
authors: Jason B
authors: JB
authors: Harper
authors: School of Chemistry, UNSW Australia , Sydney, NSW 2052, Australia.
authors: Chuan
authors: C
authors: Zhao
keywords: gas sensor; membrane-less; microarray; microcontact printing; spill-less; thiol-functionalized ionic liquids