Antimicrobial photodynamic therapy is one of the effective strategies for facing the resistance of pathogenic microorganisms of traditional antibiotics. In connection with this, new effective compounds are being sought, increasing their biological activity upon irradiation. In this work, a new polypropylene imine (PPI) from the first generation was synthesized and modified with 1,8-naphthalimide, to which a sulfonyl chloride group (D1) was introduced at the C-4 atom, from which after interaction with glucosamine, a dendrimer containing a sulphonamide group (D2) was obtained. The photophysical characteristics of dendrimer D2 were investigated in five organic solvents of different polarity and aqueous media. It was found that the absorption and fluorescence maxima are slightly affected by the polarity of the solvents. Excimer and monomeric fluorescence were also recorded with dendrimer D2 in an aqueous solution …