S. Assavapanumat, T. Yutthalekha, P. Garrigue, B. Goudeau, V. Lapeyre, A. Perro, N. Sojic, C. Wattanakit, A. Kuhn
see also CNRS press release
Concepts leading to single enantiomers of chiral molecules are of crucial importance for many applications, including pharmacology and biotechnology. Recently, mesoporous metal phases encoded with chiral information have been developed. We propose here to fine-tune the enantioaffinity of such structures by imposing an electric potential, which can influence the electrostatic interactions between the chiral metal and the target enantiomer. This allows increasing the binding affinity and thus the discrimination between two enantiomers. The concept is illustrated by generating chiral encoded metals in a microfluidic channel via the reduction of a platinum salt in the presence of a liquid crystal and L-tryptophan as a chiral model template. After removal of the template molecules, the modified microchannel retains a pronounced chiral character. Its chiral recognition efficiency can be fine-tuned by applying a suitable potential to the metal phase. This enables the separation of both components of a racemate flowing through the channel. The approach constitutes a promising and complementary strategy in the frame of chiral discrimination technologies.