A new 6-benzylaminopurine-functionalized disubstituted polyacetylene (P2) with strong green fluorescence is successfully synthesized by utilizing the postfunctional method. The polymer is soluble in common organic solvents, and its strong green fluorescence can be quenched by copper and cobalt ions with a detection limit down to 1.0 x 108 (0.64 ppb) and 3.3 x 108 mol L1 (1.94 ppb), respectively. Moreover, not much interference is observed from other metal ions, including Li+, Na+, K+, Fe3+, Fe2+, Ni2+, Hg2+, Mg2+, Al3+, Zn2+, Mn2+, Pb2+, Ba2+, Ca2+, Cd2+, Ag+, and Cr3+. Furthermore, P2 can be put into application using test strips, making P2 a practical, sensitive, and selective copper and cobalt probe.