Photodynamic inactivation of bacteria using novel electrogenerated porphyrin-fullerene C60 polymeric films

MARIA BELEN BALLATORE; JAVIER DURANTINI; NATALIA GSPONER; MARIA BELEN SUAREZ; MIGUEL GERVALDO; LUIS OTERO; MARIANA SPECIA; MARIA ELISA MILANESIO; EDGARDO DURANTINI

ENVIRONMENTAL SCIENCE & TECHNOLOGY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 vol. 49 p. 7456 - 7463

0013-936X

ABSTRACT: A porphyrin-fullerene C60 dyad (TCP-C60) substituted by carbazoyl groups was used to obtain electrogenerated polymeric films on optically transparent indium tin oxide (ITO) electrodes. This approach produced stable and reproducible polymers, holding fullerene units. The properties of this film were compared with those formed by layers of TCP/TCP-C60 and TCP/ZnTCP. Absorption spectra of the films presented the Soret and Q bands of the corresponding porphyrins. The TCP-C60 film produced a high photodecomposition of 2,2-(anthracene-9,10-diyl)bis(methylmalonate), which was used to detect singlet molecular oxygen O2(117 g) production in water. In addition, TCP-C60 film induced the reduction of nitro blue tetrazolium to diformazan in presence of NADH, indicating the formation of superoxide anion radical. Moreover, photooxidation of L-tryptophan mediated by TCP-C60 films was found in water. In biological media, photoinactivation of Staphylococcus aureus was evaluated depositing a drop with 2.5x103 21 cells on the films. After 30 min irradiation, no colony formation was detected using TCP-C60 or TCP/TCP23 C60 films. Furthermore, photocytotoxic activity was observed in cell suspensions of S. aureus and Escherichia coli. The irradiated TCP-C60 film produced a 4 log decrease of S. aureus survival after 30 min. Also, a 4 log reduction of E. coli viability was obtained using TCP-C60 film after 60 min irradiation. Therefore, TCP-C60 film is an interesting and versatile photodynamic active surface to eradicate bacteria