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Simultaneous Detection of Single Attoliter Droplet Collisions by Electrochemical and Electrogenerated Chemiluminescent Responses
Author(s) -
Dick Jeffrey E.,
Renault Christophe,
Kim ByungKwon,
Bard Allen J.
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201407937
Subject(s) - luminophore , chemiluminescence , chemistry , emulsion , ultramicroelectrode , electrochemistry , rubrene , electrochemiluminescence , ionic liquid , electrode , toluene , aqueous solution , analytical chemistry (journal) , chemical engineering , photochemistry , chromatography , organic chemistry , materials science , cyclic voltammetry , optoelectronics , luminescence , catalysis , engineering
We provide evidence of single attoliter oil droplet collisions at the surface of an ultra‐microelectrode (UME) by the observation of simultaneous electrochemical current transients ( i – t curves) and electrogenerated chemiluminescent (ECL) transients in an oil/water emulsion. An emulsion system based on droplets of toluene and tri‐ n ‐propylamine (2:1 v/v) emulsified with an ionic liquid and suspended in an aqueous continuous phase was formed by ultrasonification. When an ECL luminophore, such as rubrene, is added to the emulsion droplet, stochastic events can be tracked by observing both the current blips from oxidation at the electrode surface and the ECL blips from the follow‐up ECL reaction, which produces light. This report provides a means of studying fundamental aspects of electrochemistry using the attoliter oil droplet and offers complementary analytical techniques for analyzing discrete collision events, size distribution of emulsion systems, and individual droplet electroactivity.