New imidazole-functionalized disubstituted polyacetylene was synthesized by utilizing the postfunctional strategy. In addition, its ability to sense copper ions and alpha-amino acids by fluorescence quenching has been studied. The quenching of the fluorescence of the imidazole-functionalized disubstituted polyacetylene was observed at a very low level of Cu2+ (7.0 x 10(-7) mol . L-1). The fluorescent intensity decreased rapidly upon the increase of the concentration of the added solution of Cu2+. It was expected that the addition of alpha-amino acids to the solution of the polyacetylene/Cu2+ complex could turn on the fluorescence of the polyacetylene, if a-amino acids could remove the copper ions from the complex. Glycine, was used for testing: upon the addition of glycine the quenched fluorescence of P1 turned on immediately. The detection limit was as low as 6.0 x 10(-5) mol . L-1.