A pyrene-based highly selective turn-on fluorescent sensor for copper(II) ions and its application in living cell imaging

A new pyrene derivative (1) containing a benzothiazolenhydrazone moiety exhibited high selectivity for Cu2+ detection. In the presence of Cu2+, chemosensor 1 provided significant fluorescence enhancement, while Ag+, Ca2+, Cd2+, Co2+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ metal ions produced only minor changes in fluorescence intensity. The association constant (Ka) for Cu2+ binding to 1 had a value of 5.00 × 108 M−2. The maximum fluorescence enhancement induced by Cu2+ binding to the chemosensor was observed over the range pH 2–8.5. Our fluorescence microscopy experiments demonstrate that chemosensor 1 may have application as a fluorescent probe for detecting Cu2+ in living cells.