We report the synthesis and Zn2 + sensing of a novel coumarin-hydrazine conjugate 3-{1-[(4, 6-Dimethyl-pyrimidin-2-yl)-hydrazono]-ethyl}-chromen-2-one (3). Compound 3 can act as a neat fluorescent Zn2 + sensor by an increment in fluorescence intensity along with an appreciable red shift. Fluorescence enhancement is caused by complexation through cis-trans isomerization process in the presence of Zn2 + ion. The practical utility of 3 was demonstrated by successful test kit experiment to detect Zn2 + in water under UV-light. © 2017 Elsevier B.V.