Fig. 3: Photoreversible assembly of fluorescent ATP/AzoDiGua aggregates.

A Photoisomerization scheme of AzoDiGua upon UV and blue irradiation. B Transmission optical microscopy images and fluorescence intensity (Exc: 400 nm; Em: 650 nm) of the ATP/AzoDiGua suspension after consecutive cycles of UV (395/25 nm, 26 mW·cm⁻²) for 3 min and blue irradiation (480/30 nm, 40 mW·cm⁻²) for 3 min. The initial suspension results from the self-assembly of ATP (1 mM) and AzoDiGua (1 mM) for 10 min. The scale bars are 20 µm. C Box plots of Feret diameter (top) and Circularity (bottom) of the supramolecular aggregates obtained after each UV/blue cycle displayed in B. The number of analyzed objects is n = 659, 1012, 1044, 994 and 817 after 1, 2, 3, 4 and 5 cycles, respectively. Blue box: range from first to third quartile, horizontal blue bars: minimum and maximum (outliers excluded); horizontal black line: median; red cross: mean. All experiments are done at room temperature in 50 mM Tris HCl buffer solutions (pH = 7.4).