New hydrophobic monomer N-methacryloyl-N '-alpha-naphthylthiourea (MANTU) was synthesized and copolymerized with hydrophilic N-isopropylacrylamide by free radical copolymerization. And N,N-dimethylacrylamide was introduced to adjust the lower critical solution temperature of the resulting copolymers. Photophysics and the effect of pH of copolymer in aqueous solutions were studied by intrinsic fluorescence observations. The self-aggregation behavior was investigated by transmission electron microscopy. The amphiphilic polymers with fluorescent behavior were confirmed to be thermo- and pH-sensitive. The interaction of the tercopolymer with adenosine 5 '-monophosphate and adenosine 5 '-trisphosphate was described. Different interactions of nucleotides with the copolymer were found and possible mechanisms were discussed. (c) 2007 Wiley Periodicals, Inc.