Development of BINOL derived axially chiral molecular probe for electrochemical discrimination of tryptophan enantiomers

Abstract

Readily available, axially chiral (S)-BINOL derivative was developed as a probe to electrochemically distinguish between the tryptophan enantiomers. These enantiodiscrimination studies were successfully conducted with only a few nanogram quantity of the chiral probe. The electrochemical investigations revealed a higher current response for d-tryptophan than l-tryptophan (ID-Trp /IL-Trp = 2.319). This preferential interaction for d-tryptophan towards the (S)-BINOL derivative was further elucidated by carrying out density functional theory calculations. The key advantages of the developed method are one-step access to the chiral probe, facile and convenient loading of the probe on the electrode, the requirement of only a minuscule quantity of probe for enantiodiscrimination, and preferential selectivity of probe towards d-tryptophan.