The widespread abuse of traditional antibiotics has led to a global rise in antibiotic-resistant bacteria, which give in return unprecedented health risks. Therefore, there is a large and urgent need for the development of new, smart antibacterial agents able to efficiently kill or inhibit bacterial growth. In this study, we investigated the antibacterial activity of S, N-doped Graphene Quantum Dots (GQDs) as a light-triggered antibacterial agent. Gamma irradiation was employed as a tool to achieve one-step modification of GQDs in the presence of Lcysteine amino acid as a source of heteroatoms. X-ray Photoelectron Spectroscopy (XPS), nuclear magnetic resonance (NMR), and zeta potential measurements provided the necessary data to clarify the structure of modified dots and verify the introduction of both S- and N-atoms in GQDs structure, but also severe changes in the aromatic, sp2 domains. Namely, gamma-irradiation caused a bonding of S atoms in 1.14 at.% mainly as thiol groups, and N in 1.81 at.% as amino groups, but sp2 contribution in GQD structure was lowered from 63.00 to 4.86 at.%, as measured in dots irradiated at a dose of 200 kGy. Fluorescence quenching measurements showed that L-cysteine-modified dots are able to bind to human serum albumin. The antibacterial activity of GQDs combined with 1 and 6 h of blue light (470 nm) irradiation was tested against 8 bacterial strains. GQD-cys-25 sample provided the best results, with minimum inhibitory concentration (MIC) as low as 125 mu g/mL against S. aureus, E. faecalis, and E. coli after only 1 h of blue light exposure.

Milenković, M., Ciasca, G., Bonasera, A., Scopelliti, M., Marković, O., Verbić, T., Marković, B. T., Jovanović, S., Blue-light-driven photoactivity of L-cysteine-modified graphene quantum dots and their antibacterial effects, <<JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY>>, 2024; 250 (112818): N/A-N/A. [doi:10.1016/j.jphotobiol.2023.112818] [https://hdl.handle.net/10807/280658]

Blue-light-driven photoactivity of L-cysteine-modified graphene quantum dots and their antibacterial effects

Ciasca, Gabriele;
2024

Abstract

The widespread abuse of traditional antibiotics has led to a global rise in antibiotic-resistant bacteria, which give in return unprecedented health risks. Therefore, there is a large and urgent need for the development of new, smart antibacterial agents able to efficiently kill or inhibit bacterial growth. In this study, we investigated the antibacterial activity of S, N-doped Graphene Quantum Dots (GQDs) as a light-triggered antibacterial agent. Gamma irradiation was employed as a tool to achieve one-step modification of GQDs in the presence of Lcysteine amino acid as a source of heteroatoms. X-ray Photoelectron Spectroscopy (XPS), nuclear magnetic resonance (NMR), and zeta potential measurements provided the necessary data to clarify the structure of modified dots and verify the introduction of both S- and N-atoms in GQDs structure, but also severe changes in the aromatic, sp2 domains. Namely, gamma-irradiation caused a bonding of S atoms in 1.14 at.% mainly as thiol groups, and N in 1.81 at.% as amino groups, but sp2 contribution in GQD structure was lowered from 63.00 to 4.86 at.%, as measured in dots irradiated at a dose of 200 kGy. Fluorescence quenching measurements showed that L-cysteine-modified dots are able to bind to human serum albumin. The antibacterial activity of GQDs combined with 1 and 6 h of blue light (470 nm) irradiation was tested against 8 bacterial strains. GQD-cys-25 sample provided the best results, with minimum inhibitory concentration (MIC) as low as 125 mu g/mL against S. aureus, E. faecalis, and E. coli after only 1 h of blue light exposure.
2024
Inglese
Milenković, M., Ciasca, G., Bonasera, A., Scopelliti, M., Marković, O., Verbić, T., Marković, B. T., Jovanović, S., Blue-light-driven photoactivity of L-cysteine-modified graphene quantum dots and their antibacterial effects, <<JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY>>, 2024; 250 (112818): N/A-N/A. [doi:10.1016/j.jphotobiol.2023.112818] [https://hdl.handle.net/10807/280658]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10807/280658
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