A functional coil-rod-coil triblock copolymer containing a terfluorene unit as the rigid segment and poly(N-isopropylacrylamide) (PNIPAAm) as the flexible block was successfully synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization using terfluorene-based dithioester as the RAFT agent. The temperature-responsive optical properties were investigated with the aid of dynamic light scattering and fluorescence techniques. Additionally, the relationship between the optical properties and the reversible phase transition of the doping system formed by blending the copolymer with tetraphenylporphine tetrasulfonic acid was studied. Above the lower critical solution temperature, the energy transfer efficiency decreased as a result indicates that these copolymers have a potential to be used as responsive fluorescent probes in facile detection of dye-labeled biopolymers.