A quinolinyl antipyrine based fluorescence sensor for Zn2+ and its application in bioimaging

By incorporating 4-aminoantipyrine moiety onto 8-aminoquinoline with a suitable spacer, a highly selective and sensitive fluorescent Zn2+ sensor, QPA, was designed and constructed. In 25% ACN-HEPES buffer pH 7.0 solution, QPA exhibited 10.6-fold fluorescence enhancement at 500 nm upon addition of Zn2+. The limit of detection (LOD) was calculated to be 1.3 x 10(-7) M according to fluorescence titration. The 1 : 1 binding mode of the metal complex was established by combined UV-vis, fluorescence and HRMS spectroscopic method. The membrane permeability of QPA to living cells and bioimaging of Zn2+ are demonstrated.