The dynamics of a rhodamine X-labeled oligonucleotide composed of 25 mers of thymine (dT(25)-ROX) in solution or adsorbed on the thermosensitive shell of poly(methyl methacrylate/N-isopropylacrylamide), poly(MMA/NIPAM), core-shell nanoparticles, with a characteristic: volume phase transition temperature (T-VPT) at similar to32 degreesC, were studied as a function of temperature by fluorescence anisotropy. The time-resolved anisotropy decay of the dT(25)-ROX oligonucleotides in buffered solution (pH 5.5) is biexponential. The results are interpreted in terms of the "two-step" model, where the fast correlation time (theta(w)) is attributed to the restricted "wobbling" motion of the bound ROX to the oligonucleotide (ODN) strand in a cone, while the slow correlation time (theta(oligo)) is related to the rotation of the oligonucleotide as a whole. Both correlation times decrease with temperature due to the variation of the viscosity of the medium. The anisotropy decays of dT(25)-ROX adsorbed on the PNIPAM thermosensitive shell were interpreted in terms of two models: the "wobbling-in-two-cones" and the heterogeneous population model. In both models, the fast correlation time is due to the "wobbling" motion of ROX (theta(w)). The half-angle of the cone of the ROX "wobbling" motion (phi) decreases from similar to34degrees below the VPT to similar to11degrees above it, due to the increasing constraints imposed by the PNIPAM chains. The slow correlation time describes the overall rotational motion of the ODN's (theta(oligo)) without restrictions (heterogeneous population model) or restricted to the "wobbling" in a cone ("wobbling-in-two-cones" model). The theta(oligo) values of the adsorbed ODNs are higher than in solution and increase with temperature from similar to2.6 ns at 15 degreesC to reach a constant value of similar to6.6 ns after the transition due to the increasing friction by the PNIPAM chains. The anisotropy decay shows a residual component at long times (r(infinity)) that increases with temperature along the VPT, which is essentially due to the increasing percentage of immobilized ODNs from similar to14% at 15 degreesC to similar to70% above the transition (heterogeneous population model) or to the increase of the order parameter, S-oligo, with temperature from 0.38 (phi(oligo) similar to 60degrees) at 15 degreesC to 0.85 (phi(oligo) similar to 27degrees) at 45 degreesC ("wobbling-in-two-cones" model). Both models show that the whole motion of the ODNs and the randomization of their orientations are strongly restricted along the volume phase transition of the PNIPAM shell.