Photoactive cotton fabric: Synthesis, characterization and antibacterial evaluation of anthraquinone-based dyes linked to cellulose

In the present work, we report a facile and low-cost method for the preparation of cotton fabric, covalently linked to three anthraquinonic (ANQs) dyes, as efficient cellulosic material with antimicrobial properties under visible light irradiation. The modified cotton fabrics were characterized by infrared (FTIR), diffuse reflectance UV-Vis spectroscopy (DRUV), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) techniques, in order to confirm the linkage between ANQs and cellulosic fibers. The antimicrobial activity of modified cotton fibres was evaluated under irradiation (400-800 nm) against Escherichia cob. The results showed the high bactericidal potential of materials with inhibition up to 99,9%. The self-cleaning phototoxic activity, due to the highly reactive singlet oxygen (O-1(2)), was confirmed by the characteristic phosphorescence emission of this transient in 1270 nm.