Photodynamic Inactivation of Bacteria Using Novel Electrogenerated Porphyrin-Fullerene C₆₀ Polymeric Films

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((1)Δg) production in water. In addition, the TCP-C60 film induced the reduction of nitro blue tetrazolium to diformazan in the 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 2.5 × 10(3) cells on the films. After 30 min irradiation, no colony formation was detected using TCP-C60 or TCP/TCP-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 the TCP-C60 film after 60 min irradiation. Therefore, the TCP-C60 film is an interesting and versatile photodynamic active surface to eradicate bacteria.

A Perspective on the Trends and Challenges Facing Porphyrin‐Based Anti‐Microbial Materials

“…In a work demonstrated in 2015, photoinactivation in the presence of these films on S. aureus and E. coli resulted in a 4log decrease of S. aureus colony after 30 minutes and a 4log reduction of E. coli viability after 60 min irradiation. ( Figure ) Therefore, a fullerene‐porphyrin thin film on electrodes approach presents an interesting and versatile surface for the eradication of harmful bacteria in water …”

Mannose‐Functionalized Hyperbranched Polyglycerol Loaded with Zinc Porphyrin: Investigation of the Multivalency Effect in Antibacterial Photodynamic Therapy

“…[39] The bands are slightly broadened, which is known for porphyrins connected top olymers. [40] Onee xplanation could be ah ydrophobic interaction and p-stackinge ffects from aggregation of the porphyrinmannose-hPG 19.5 conjugates. [40,41] Given that the conjugates are highly fluorescent( see FigureS28 and S29 in the Supporting Information), they are ideal candidates for investigation with fluorescencespectroscopy.…”

Zinc porphyrin/fullerene/block copolymer micelle for enhanced electron transfer ability and stability

“…In this work, the photoinduced superoxide radical oxygen generation was detected by NBT method. 52 The reduction of NBT to formazan was used in the presence of reduced nicotinamide adenine dinucleotide (NADH) showed in Fig. 5F.…”