▎ 摘　　要

Two new composites containing perylene diimides derivates covalently bonded to graphene oxide were obtained and their antimicrobial properties were applied against Escherichia coli, a model of gram-negative bacteria. The perylene diimides were prepared by condensating perylene dianhydride with ethyldiamine (PEDI2) or decyldiamine (PEDI10) and then, a SOCl2 modified GO sample reacted with perylene diimides, originating the respective covalently bonded GO/PEDI2 and GO/PEDI10. Semi-empirical calculations with PM6-DH2X (MOPAC 2016) confirmed the photophysical results and showed that perylene diimides could form three different structures when bonded to GO: (1) parallel to GO, forming pi-stacking interaction; (2) parallel to GO, but not superimposed x-systems (pns-pi), and; (3) perpendicular to the GO molecular plane (T-shape). The photophysical studies showed that both GO/PEDI2 and GO/PEDI10 composites were able to generate singlet oxygen (O-1(2) ) when perylene diimides did not form pi-stacking with GO. Finally, the photochemical reactivities of such covalently bonded composites were confirmed by the increased bacterial inhibition when E. coli (more than 80 %) is irradiated in the visible part of the electromagnetic spectrum when compared to dark conditions GO.