A fluorescent monomer of boron dipyrromethene (BODIPY) derivative (9AnPD) is designed and synthesized at first, and then it is introduced into polyurethane to obtain polymeric chemosensor with dangling fluorescent side groups. The monomer chemosensor 9AnPD exhibits highly selective properties to Hg2+ ion in a wide pH range. The color of the monomer changed rapidly upon the addition of Hg2+ ion. The fluorescence peak shifted and is enhanced about 4-flod. In addition, the monomer chemosensor reaches the detection limit of Hg2+ is as low as 5 x 10(-6) M. When the fluorescent monomer is introduced to polymers, the sensing properties of the monomer chemosensor 9AnPD still remained. The polymer chemosensors not only exhibit fluorescence shift and color change for identifying Hg2+ ion as its monomer chemosensor, but also improve the efficiency of detection. The detection limit of polymer chemosensor could reach 5 x 10(-7) M, and the fluorescence enhanced about 6-flod. The glass transition temperature (T-g) of the fluorescent PU is increased with the introduction of 9AnPD. However, it is about 60 degrees C, and will not lead to any adverse effect for the process. The molecular weights of PUs are lower than which without 9AnPD, but still of the macromolecular level. (C) 2017 Elsevier B.V. All rights reserved.