Abstract
Anion exchange polystyrene nanofiber materials (AE) were prepared by electrospinning followed by two-step functionalization of the nanofiber surface by chlorosulfonic acid and ethylendiamine. The photoactive character of these materials was introduced through adsorption of the tetra-anionic 5,10,15,20-tetra-kis-(4-sulfonatophenyl) porphyrin photosensitizer (TPPS-AE) on the nanofiber surface or by encapsulation of the nonpolar 5,10,15,20-tetraphenylporphyrin photosensitizer (AE(TPP)) into the nanofibers.
Anion exchange nanofiber materials with porphyrins are characterized by a high ion-exchange capacity, photo-generation of singlet oxygen O-2((1)Delta(g)), and singlet oxygen-sensitized delayed fluorescence. Due to the photogeneration of cytotoxic O-2((1)Delta(g)), the nanofibers exhibited oxidation of the external substrates in aqueous solution and an efficient antibacterial effect when activated by simulated daylight.
Adsorption of both TPPS and I(-)on the surface of AE led to the formation of more efficient I-TPPS-AE materials. Rapid photooxidation of I(-)by O-2((1)Delta(g)), and the formation of another cytotoxic species, I-3(-), on the surface of the nanofibers were responsible for the increased antibacterial properties of I-TPPS-AE and the prolonged antibacterial effect in the dark.