Dynamic light scattering (DLS) and transmission electron microscopy (TEM) are used to characterize the size and morphology of 2C-WP5A+G assembly. As shown in Fig. 5a, DLS data showed that 2C-WP5A+trans-G formed well-defined aggregates with a narrow size distribution, giving an average diameter about 848 nm at a scattering angle of 90°. Meanwhile, the TEM image (Fig. 5c) also certificated the formation of spherical nanoparticles with diameter about 800 nm consistent with the DLS data. Furthermore, after irradiation the solution with UV light at 365 nm for 10 min, the solution became clear and the size of the aggregates formed by 2C-WP5A+cis-G changed into smaller nanoparticles with diameter about 253 nm (Fig. 5b,d). Afterwards, upon heating the solution at 80 °C for one hour, the size of the aggregates returned to the original status. So it is incontrovertible that the isomerization of G by photo/thermal stimulation has significant influence on the size and morphology of the supramolecular nanoparticles assembly.