A chiral perazamacrocyclic fluorescent sensor for cascade recognition of Cu(II) and the unmodified α-amino acids in protic solutions.

A novel chiral Perazamacrocyclic fluorescent sensor (1) was designed and synthesized. It can serve as a fluorescent turn-off sensor with high selectivity toward Cu(II) among 14 metal ions. Furthermore, though 1 exhibits no enantioselectivity, after adding Cu(II), the in situ generated Cu(II)-containing complex of 1 (Cu(II)-1) can exhibit remarkable fluorescent enhancement responses and considerable enantioselectivities toward unmodified α-amino acids in protic solutions via a ligand displacement mechanism; i.e. a cascade recognition of Cu(II) and unmodified α-amino acids has been achieved.