Interaction and aggregation of iron oxide γ-Fe2O3 nanoparticles with a 1,8-Naphthalimide derivative

The interaction of a fluorescent molecule 4-methoxy-N-[2-(1-pyrrolidine)ethyl]-1,8-naphthalimide (MNN) with iron oxide γ-Fe2O3 (maghemite) nanoparticles (IONPs) in water is demonstrated through fluorescence, Nuclear Magnetic Resonance (1H NMR) and Dynamic Light Scattering (DLS) measurements at different molar proportions (MNN:IONP). The 1H NMR measurements suggest that the main interaction occurs in the substituent in position 4 of the naphthalene ring. DLS measurements show full aggregation of the IONPs with the MNN molecules for the concentration used. The results suggest that the system could be used for local laser induced heat treatment while localizing the IONPs via the fluorescence of the attached fluorescent molecule.