An efficient chiral sensing platform based on graphene quantum dot-tartaric acid hybrids

Graphene quantum dots (GQDs) and tartaric acid (TA) were successively electrodeposited onto the surface of a glassy carbon electrode (GCE). Due to the intrinsic chirality of L-(+)-TA and D-(-)-TA and the signal amplification function of GQDs, the GQDs-TA hybrid modified GCE could be regarded as an efficient electrochemical chiral sensing platform and used for chiral recognition of tryptophan (Trp) isomers. The recognition efficiency with the proposed GQDs-TA is significantly higher than that with TA alone. Of particular interest, GQDs-L-(+)-TA and GQDs-D-(-)-TA exhibit completely opposite selectivity toward L-Trp and D-Trp. Also in this work, the pH-sensitive enantiorecognition of the GQDs-TA hybrids was investigated.