Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots
Due to the increasing number of bacterial infections and the development of resistivity toward antibiotics, new materials and approaches for treatments must be urgently developed. The production of new materials should be ecologically friendly considering overall pollution with chemicals and economi...
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MDPI AG
2022-09-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/19/6525 |
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| author | Svetlana Jovanovic Aurelio Bonasera Sladjana Dorontic Danica Zmejkoski Dusan Milivojevic Tamara Janakiev Biljana Todorovic Markovic |
| author_facet | Svetlana Jovanovic Aurelio Bonasera Sladjana Dorontic Danica Zmejkoski Dusan Milivojevic Tamara Janakiev Biljana Todorovic Markovic |
| author_sort | Svetlana Jovanovic |
| collection | DOAJ |
| description | Due to the increasing number of bacterial infections and the development of resistivity toward antibiotics, new materials and approaches for treatments must be urgently developed. The production of new materials should be ecologically friendly considering overall pollution with chemicals and economically acceptable and accessible to the wide population. Thus, the possibility of using biocompatible graphene quantum dots (GQDs) as an agent in photodynamic therapy was studied. First, dots were obtained using electrochemical cutting of graphite. In only one synthetic step using gamma irradiation, GQDs were doped with N atoms without any reagent. Obtained dots showed blue photoluminescence, with a diameter of 19–89 nm and optical band gap of 3.23–4.73 eV, featuring oxygen-containing, amino, and amide functional groups. Dots showed antioxidative activity; they quenched •OH at a concentration of 10 μg·mL<sup>−1</sup>, scavenged DPPH• radicals even at 5 μg·mL<sup>−1</sup>, and caused discoloration of KMnO<sub>4</sub> at 30 μg·mL<sup>−1</sup>. Under light irradiation, dots were able to produce singlet oxygen, which remained stable for 10 min. Photoinduced effects by GQDs were studied on several bacterial strains (<i>Listeria monocytogenes</i>, <i>Bacillus cereus</i>, clinical strains of <i>Streptococcus mutans</i>, <i>S. pyogenes</i>, and <i>S. sangunis</i>, <i>Pseudomonas aeruginosa</i>, and one yeast strain <i>Candida albicans</i>) but antibacterial effects were not noticed. |
| first_indexed | 2024-03-09T21:32:02Z |
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| id | doaj.art-0a241a5c533541f1a26b961d4265ff05 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T21:32:02Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-0a241a5c533541f1a26b961d4265ff052023-11-23T20:52:18ZengMDPI AGMaterials1996-19442022-09-011519652510.3390/ma15196525Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum DotsSvetlana Jovanovic0Aurelio Bonasera1Sladjana Dorontic2Danica Zmejkoski3Dusan Milivojevic4Tamara Janakiev5Biljana Todorovic Markovic6Institute of Nuclear Sciences—National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovica Alasa 12-14, 11000 Belgrade, SerbiaDepartment of Physics and Chemistry, Emilio Segrè, University of Palermo, 90128 Palermo, ItalyInstitute of Nuclear Sciences—National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovica Alasa 12-14, 11000 Belgrade, SerbiaInstitute of Nuclear Sciences—National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovica Alasa 12-14, 11000 Belgrade, SerbiaInstitute of Nuclear Sciences—National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovica Alasa 12-14, 11000 Belgrade, SerbiaFaculty of Biology, University of Belgrade, Studentski Trg 16, 11158 Belgrade, SerbiaInstitute of Nuclear Sciences—National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovica Alasa 12-14, 11000 Belgrade, SerbiaDue to the increasing number of bacterial infections and the development of resistivity toward antibiotics, new materials and approaches for treatments must be urgently developed. The production of new materials should be ecologically friendly considering overall pollution with chemicals and economically acceptable and accessible to the wide population. Thus, the possibility of using biocompatible graphene quantum dots (GQDs) as an agent in photodynamic therapy was studied. First, dots were obtained using electrochemical cutting of graphite. In only one synthetic step using gamma irradiation, GQDs were doped with N atoms without any reagent. Obtained dots showed blue photoluminescence, with a diameter of 19–89 nm and optical band gap of 3.23–4.73 eV, featuring oxygen-containing, amino, and amide functional groups. Dots showed antioxidative activity; they quenched •OH at a concentration of 10 μg·mL<sup>−1</sup>, scavenged DPPH• radicals even at 5 μg·mL<sup>−1</sup>, and caused discoloration of KMnO<sub>4</sub> at 30 μg·mL<sup>−1</sup>. Under light irradiation, dots were able to produce singlet oxygen, which remained stable for 10 min. Photoinduced effects by GQDs were studied on several bacterial strains (<i>Listeria monocytogenes</i>, <i>Bacillus cereus</i>, clinical strains of <i>Streptococcus mutans</i>, <i>S. pyogenes</i>, and <i>S. sangunis</i>, <i>Pseudomonas aeruginosa</i>, and one yeast strain <i>Candida albicans</i>) but antibacterial effects were not noticed.https://www.mdpi.com/1996-1944/15/19/6525graphene quantum dotsN-dopinggamma-irradiationphotoluminescencephotodynamic therapyantioxidant |
| spellingShingle | Svetlana Jovanovic Aurelio Bonasera Sladjana Dorontic Danica Zmejkoski Dusan Milivojevic Tamara Janakiev Biljana Todorovic Markovic Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots Materials graphene quantum dots N-doping gamma-irradiation photoluminescence photodynamic therapy antioxidant |
| title | Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots |
| title_full | Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots |
| title_fullStr | Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots |
| title_full_unstemmed | Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots |
| title_short | Antioxidative and Photo-Induced Effects of Different Types of N-Doped Graphene Quantum Dots |
| title_sort | antioxidative and photo induced effects of different types of n doped graphene quantum dots |
| topic | graphene quantum dots N-doping gamma-irradiation photoluminescence photodynamic therapy antioxidant |
| url | https://www.mdpi.com/1996-1944/15/19/6525 |
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