It is also required to make a thorough inquiry about the repetitiveness of the photo/thermal driven size switching of the supramolecular assembly. Size switching process was determined by monitoring the optical transmittance of 2C-WP5A+G solution at 600 nm (Fig. 6) and DLS experiment (see Supplementary Fig. S22). The presence of the large aggregates of the solution was evident from the decrease in transmittance, which was corresponding to the formation of spherical nanoparticles with diameter of 800 nm from DLS and TEM results. After irradiation with UV light at 365 nm for 10 min, the solution turned clear and transparent with nearly 100% transmittance. By continuous heating at 80 °C for one hour, the solution reverted to the initial turbidity state. Significantly, the reversible transition between turbidity and clarity could repeat several times, indicating that the good photo/thermal responsiveness of the supramolecular assembly.