A displacement method of detecting hydrogen sulfide in aqueous media based on complex L-Cu ensemble is developed. Once combined with Cu<sup>2+</sup>, complex L-Cu displayed high specificity for sulfide anion. Among the various anions, only sulfide anion induce the revival of fluoresecence of compound L, which is quenched by Cu<sup>2+</sup>, resulting in turn-on type sensing sulfide anion. Complex L-Cu exhibits a highly sensitive fluorescent response toward S<sup>2-</sup> by releasing compound L to give a remarkable change with 20-fold fluorescence intensity enhancement under 2 equivalent of S<sup>2-</sup> added in Tris-HCl/ DMF (20 mM, 6/4, v/v), and also exhibits a dynamic response range for S<sup>2-</sup> from 5×10<sup>-7</sup> to 5×10<sup>-6</sup> M, with a detection limit of 0.18 μM. In addition, the turn-on fluorescent change upon the addition of S<sup>2-</sup> is also applied in cell imaging.©2013 PublishedbyElsevierB.V.