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

Abstract

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 × 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.