A ratiometric fluorescent probe for oxalate based on alkyne-conjugated carboxamidoquinolines in aqueous solution and imaging in living cells

A novel ratiometric fluorescent probe for oxalic acid was designed and synthesized, based on the zinc-containing [DAQZ@2Zn(2+)] complex. It shows highly selective on-off fluorescence changes with a more than 20 nm blue shift in wavelength for oxalic acids in aqueous solution. Moreover, it can fluorescently respond to oxalic acid in living cells.