Electrochemiluminescent chiral discrimination with chiral Ag2S quantum dots/few-layer carbon nitride nanosheets.

Well-dispersed chiral Ag2S quantum dots (Ag2S QDs) were facilely synthesized by using N-acetyl-L-cysteine (NALC) as the chiral ligand and loaded onto nanosheets of two-dimensional (2D) few-layer carbon nitride (C3N4). The resultant nanocomposite (Ag2S QDs/few-layer C3N4) shows enhanced electrochemiluminescence (ECL) while maintaining the chirality of Ag2S QDs, which can be used for the chiral discrimination of the enantiomers of tyrosine (Tyr). Due to the higher affinity of chiral Ag2S QDs toward L-Tyr than toward its enantiomer, the ECL intensity of Ag2S QDs/few-layer C3N4 is significantly decreased after its incubation with L-Tyr, and thus the Tyr enantiomers can be discriminated. The developed ECL chiral sensor exhibits high stability and reproducibility. The universality of the ECL chiral sensor for the discrimination of other chiral amino acids is also studied, and the results indicate that it can work only in the case of chiral aromatic amino acids.