A Pyrene-based Highly Selective Turn-on Fluorescent Sensor for Copper(II) Ion and its Application in Live Cell Imaging

Abstract

A new pyrene derivative (chemosensor 1) containing a picolinohydrazide moiety exhibits high selectivity for Cu2+ ion detection in mixed aqueous media (CH3OH:H2O=7:3). Significant fluorescence enhancement was observed with chemosensor 1 in the presence of Cu2+. However, the metal ions Ag+, Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ produced only minor changes in fluorescence for the system. The apparent association constant (K-a) of Cu2+ binding in chemosensor 1 was found to be 2.75*10(3) M-1. The maximum fluorescence enhancement caused by Cu2+ 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 Cu2+ in living cells.