ABSTRACT
A new pyrene-based chemosensor (1) exhibits excellent selectivity for Fe(3+) ions over a wide range of tested metal ions Ag(+), Ca(2+), Cd(2+), Co(2+), Cu(2+), Fe(2+), Hg(2+), K(+), Mg(2+), Mn(2+), Ni(2+), Pb(2+), and Zn(2+). The binding of Fe(3+) to chemosensor 1 produces an emission band at 507 nm due to the formation of a Py-Py* excimer that is induced by Fe(3+)-binding. The binding ratio of 1-Fe(3+) was determined to be 1:1 from a Job plot. The association constant of 1-Fe(3+) complexes was found to be 1.27 × 10(4) M(-1) from a Benesi-Hildebrand plot. In addition, fluorescence microscopy experiments show that 1 can be used as a fluorescent probe for detecting Fe(3+) in living cells.
Subject(s)
Ferric Compounds/analysis , Fluorescent Dyes/chemistry , Pyrenes/chemistry , Fluorescent Dyes/chemical synthesis , HeLa Cells , Humans , Ions/analysis , Molecular Structure , Pyrenes/chemical synthesis , Quantum Theory , Spectrometry, Fluorescence/instrumentation , Tumor Cells, CulturedABSTRACT
A new pyrene derivative (chemosensor 1) containing a picolinohydrazide moiety exhibits high selectivity for Cu(2+) ion detection in mixed aqueous media (CH(3)OH:H(2)O = 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 (K(a)) of Cu(2+) binding in chemosensor 1 was found to be 2.75*10(3) 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.
