Hybrid light-emitting devices for the straightforward read-out of chiral information

Abstract : Bipolar electrochemistry has gained increasing attention in recent years as an attractive transduction concept in analytical chemistry in general, and more specifically in the frame of chiral recognition. Herein, we use this concept of wireless electrochemistry, based on the combination of the enantioselective oxidation of a chiral probe with the emission of light from a light emitting diode (LED), as an alternative for an easy and straightforward read-out of the presence of chiral molecules in solution. A hybrid polymer-microelectronic device was designed, using an inherently chiral oligomer i.e. oligo-(3,3’-dibenzothiophene) and a polypyrrole strip as the anode and cathode of a miniaturized LED. The wireless induced redox reactions trigger light emission when the probe with the right chirality is present in solution, whereas no light emission is observed for the opposite enantiomer. The average light intensity shows a linear correlation with the analyte concentration and the concept opens the possibility to quantify the enantiomeric excess in mixtures of the molecular antipodes.