Straightforward enantioselective
analytical methods are very important
for drug safety, considering that in certain cases one of the two
enantiomers of a chiral molecule might be harmful for humans. In this
work, we propose a simple system for the direct and easy read-out
of the enantiomeric excess of 3,4-dihydroxyphenylalanine (DOPA) as
a model analyte. A conducting oligomer, i.e. oligo-(3,3′-dibenzothiophene),
bearing inherently chiral features, is electrogenerated on a polypyrrole
film. The resulting freestanding hybrid material is used as a wireless
enantioselective actuator in a bipolar electrochemical cell. Combining
in a single setup two individual actuators with opposite chiral features
allows a direct visual read-out of enantiomeric excess, as the bending
amplitude of each of the two actuators is directly correlated with
the concentration of the corresponding stereoisomer of the analyte.
Optimization of the experimental parameters results in efficient bending,
giving access to the percentage values of the enantiomeric excess
in mixtures containing different ratios of the antipodes, thus opening
the way to potential applications for chiral in situ analysis.