A novel 1,2,3-triazolyl-linked 8-hydroxyquinoline (8-HQ) dimer, as a selective turn-on fluorescent sensor for Cd2+ was efficiently synthesized from the "click" reaction and gave weaker fluorescence in protic solvents and water-based mixture solvent (CH3CN/H2O = 5/95, v/v). This sensor showed highly selective turn-on fluorescence for Cd2+ over Zn2+ within a broad pH range in aqueous solution (CH3CN/H2O = 5/95, v/v).