Generation and Mixing of Subfemtoliter Aqueous Droplets on Demand

Published

August 27, 2009

Author(s)

Kristian Helmerson, Jianyong N. Tang, Ana Jofre, Rani Kishore, Joseph E. Reiner, Mark E. Greene, Geoffrey M. Lowman, John Denker, Christina N. Willis, Lori Goldner

Abstract

We describe a novel method of generating monodisperse sub-femtoliter aqueous droplets on demand by means of piezoelectric injection. Droplets with volumes down to 200 aL are generated by this technique. The droplets are injected into a low refractive index perfluorocarbon so that they can be optically trapped. We demonstrate the use of optical tweezers to manipulate and mix droplets. For example, using optical tweezers we bring two droplets, one containing a calcium sensitive dye and the other calcium chloride, into contact. The droplets coalesce with a resulting reaction time of about 1 ms. The monodispersity, manipulability, repeatability, small size, and fast mixing afforded by this system offer many opportunities for nanochemistry and observation of chemical reactions on a molecule-by-molecule basis.

Citation

Analytical Chemistry

Volume

81

Issue

19

Pub Type

Journals

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Keywords

droplet, droplet on demand, femtoliter, microemulsion, microreactors, perflurocarbon, optical tweezers

Citation

Helmerson, K. , Tang, J. , Jofre, A. , Kishore, R. , Reiner, J. , Greene, M. , Lowman, G. , Denker, J. , Willis, C. and Goldner, L. (2009), Generation and Mixing of Subfemtoliter Aqueous Droplets on Demand, Analytical Chemistry, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=902858 (Accessed January 21, 2025)