Indicator displacement sensor for efficient determination of α-hydroxydicarboxylic acids and their chiral discrimination

An indicator displacement sensing ensemble, composed of bis-Cinchona alkaloid diimide triad (A) and bromophenol blue (I), was developed for easy and efficient assay of α-hydroxcarboxylic acids with a high affinity for tartrates, for which the detection limit of 0.015 mg/ml was achieved. This system also discriminates enantiomeric α-hydroxycarboxylic acids and can be used for quick quantitative determination of natural tartaric acid in wine.