Copolymers bearing azacrown ether and anthracene moieties were synthesized using methacrylates of N-2-ethyl-azacrown ether or 9-hydroxymethylanthracene. Their fluorescence behaviors in the presence of alkali metal ions were measured in THF:H(2)O = 10:1 solution. Maximum fluorescence intensities for copolymers bearing aza-12-crown-4, 15-crown-5 and 18-crown-6 were observed for with Na(+), K(+) and K(+), respectively. The largest change in fluorescence behavior was observed for the copolymer bearing aza-18-crown-6 in the presence of K(+). The magnitude of the increase in the fluorescence intensity was related to the content of the crown ether moiety. The time-dependent changes in the fluorescence spectra using photo-irradiation were also investigated. (c) 2011 Elsevier Ltd. All rights reserved.