Fluorescent conjugated polymers gained interest in the last decades for both imaging and targeting tumor cells for the purpose of diagnosis and treatment of cancer. In the light of this objective conjugated poly(p-phenylene) possessing beta-cyclodextrin (beta-CD) units in the main chain and poly(ethylene glycol) side chains is used as an imaging and therapeutic agent to target U87 and Vero cells. Additionally, imaging quality and therapy efficiency of the bare graft copolymer and its gold nanoparticle (AuNP) conjugated form were investigated and compared. It is observed that beta-CD is effective not only for the imaging of the tumor cells, but also as a radiotherapy agent. Conjugation of the polymer with the AuNPs provides significant improvement in the therapeutic efficiency. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47250.