Fluorescence relay enhancement sequential recognition of Cu2+ and CN− by a new quinazoline derivative

Sequential recognition of Cu2+ and CN− by a new benzimidazole-containing quinazoline based probe (1) has been achieved. Probe 1 exhibits highly selective and sensitive fluorescence “off-on” recognition properties to Cu2+ in CH3CH2OH/H2O (1/1, v/v, HEPES 20 mM, pH 7.0) solution with a 2:1 binding stoichiometry. The in situ prepared 1-Cu2+ complex solution displays high selectivity to CN− through fluorescence relay enhancement. This Cu2+ and CN− sequential recognition via fluorescence relay enhancement make probe 1 has a potential utility for Cu2+ and CN− detection in aqueous media.