Design and preparation of a novel fluorescent naphthalimide derivative supramolecular self-assembly system and its bioimaging application

A novel fluorescent naphthalimide derivative gelator (N-18) was designed and characterised which could form a stable gel in 1,4-dioxane/H2O (2/1, v/v), methyl sulfoxide (DMSO), ethanol/H2O (4/1, v/v), acetone/H2O (2/1, v/v) and methanol. The self-assembly process of molecule N-18 in the five solvents was carefully investigated by the field emission scanning electron microscope, UV-vis absorption spectra, fluorescence emission spectra, fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and water contact angle experiments. Different structures from microbelts to helical nanofibers were formed in the self-assembly process. Hydrogen bonding and pi-pi stacking interaction were the mainly driving forces for the formation of gel. At the same time, the hydrophobic surface with the contact angles of 133 degrees-142 degrees was observed on the xerogel films N-18 from the above five solvents. Interestingly, molecule N-18 could be applied in bioimaging in a living cell. [GRAPHICS] .