In this study, the synthesis of new thermoactive polymer nanoparticles with a hollow and porous structure is reported. The nanoparticles consist of viologen cavitands linked with styrene bridges. The sizes of the nanoparticles and their pores are sensitive to temperature change. The temperature increase results in the swelling of the nanoparticles and in an increase in the permeability of the nanoparticle shell. The nanoparticles are characterized by the data of NMR, IR, and UV spectroscopies, and dynamic and static light scattering (DLS, SLS). The electrochemical behavior of the nanoparticles was investigated with cyclic voltammetry. The nanoparticles can be applied to the temperature-controlled binding and release of substrates as shown by the fluorescent dye rhodamine B. The nanoparticles encapsulate and release rhodamine B in response to the change in temperature from 25 to 40 °C.