Ionic liquid-based compound droplet microfluidics for 'on-drop' separations and sensing

• Published in: Lab on a chip Vol. 10; no. 18; pp. 2458 - 2463
• Main Authors: Barikbin, Zahra, Rahman, Md Taifur, Parthiban, Pravien, Rane, Anandkumar S, Jain, Vaibhav, Duraiswamy, Suhanya, Lee, S H Sophia, Khan, Saif A
• Format: Journal Article
• Language: English
• Published: England 21.09.2010
• Subjects: Chemistry Techniques, Analytical - instrumentation; Coloring Agents - analysis; Coloring Agents - chemistry; Coloring Agents - isolation & purification; Droplets; Fluid dynamics; Fluid flow; Fluids; Hydrogen-Ion Concentration; Ionic liquids; Ionic Liquids - chemistry; Mathematical analysis; Microfluidic Analytical Techniques; Microfluidics; Organic Chemicals - analysis; Organic Chemicals - chemistry; Organic Chemicals - isolation & purification; Separation; Water - chemistry
• ISSN: 1473-0197; 1473-0189
• DOI: 10.1039/c004853d

We present a new and general scheme for analytical applications of droplet-based microfluidics in which flowing droplets function not only as isolated reaction flasks, but are also capable of on-drop separation and sensing. To demonstrate this, we choose ionic liquids as designer fluids whose chemical and physical properties can be tailored in task-specific fashion. We create aqueous-ionic liquid compound droplets with tunable structures using an imidazolium-based ionic liquid, and present two analytical applications-separation of a binary aqueous mixture of organic dyes and dynamic pH sensing-to highlight the salient features of this scheme. By combining designer fluids with designer microfluidic emulsions, our work opens up a rich space of exploration for analytical microfluidics.