An acrylic monomer bearing couamrin moiety, 7-hydroxy-4-methyl-8-(4'-acryloylpiperazin-1'-yl) methylcoumarin (Ac-HMPC) was synthesized from 7-hydroxy-4-methyl-8-(4'-piperazin-1'-yl)methyl coumarin (HMPC) and acryloyl chloride (Ac) in the presence of triethylamine in dry dichloromethane (CH2Cl2) under 0 degrees C. The synthesized Ac-HMPC was identified by FTIR, MS and H-1 NMR spectra, respectively. Then it was copolymerized with acrylamide (AM) using AIBN as initiator in THF under 70 degrees C. The main photophysical properties of the fluorescent copolymer (poly(Ac-HMPC-co-AM)) were determined viewing its sensor for protons and metal cations, The fluorescent polymer displayed "on-off' switching in its fluorescence intensity over a wide pH scale. In addition, it was found the fluorescence enhancement of poly(Ac-HMPC-co-AM) in the presence of Ni2+ ion. The results suggest that copolymer may offer potential as a reusable polymer for sensor protons and Ni2+ ion in aqueous solution. (c) 2008 Elsevier Ltd. All rights reserved.