A new pyrene derivative (chemosensor 1) containing a picolinohydrazide moiety exhibits high selectivity for Cu 2+ ion detection in mixed aqueous media (CH3OH:H2O= 7:3). Significant fluorescence enhancement was observed with chemosensor 1 in the presence of Cu 2+. However, the metal ions Ag+, Ca 2+, Cd 2+, Co 2+, Cu 2+, Fe 2+, Fe 3+, Hg 2+, K+, Mg 2+, Mn 2+, Ni 2+, Pb 2+, and Zn 2+ produced only minor changes in fluorescence for the system. The apparent association constant (Ka) of Cu 2+ binding in chemosensor 1 was found to be 2.75103 M-1. The maximum fluorescence enhancement caused by Cu 2+ binding in chemosensor 1 was observed over the pH range 5-8. Moreover, by means of fluorescence microscopy experiments, it is demonstrated that 1 can be used as a fluorescent probe for detecting Cu 2+ in living cells.
- Live cell imaging