Sensing tyrosine enantiomers by using chiral CdSe/CdS quantum dots capped with N-acetyl-l-cysteine

Despite of the importance of enantiomers , the fluorescence sensing of enantiomers and the interpretation of the “preferential interaction” still remain insufficiently explored. In this study, we report the recognition of tyrosine (Tyr) enantiomers by chiral N -acetyl- L -cysteine ( L -NAC) capped CdSe/CdS quantum dots (QDs) under alkaline experimental condition. L -Tyr could greatly quench the fluorescence of CdSe/CdS QDs, while D -Tyr displayed no effect on the fluorescence. The one-step synthesized chiral L -NAC-CdSe/CdS QDs demonstrated high selectivity for Tyr enantiomers. In particular, the mechanism of chiral recognition has been studied by UV/vis absorption spectra and circular dichroism (CD) spectra. The changes of intensity and sign of CD spectra corroborated the attachment of L -Tyr to the surface of QDs, which may be valuable aids in obtaining a better understanding of the possible mechanism of enantioselective recognition.