Carbon quantum dots: A bright future as photosensitizers for in vitro antibacterial photodynamic inactivation

Natural carbon-based quantum dots and their applications in drug delivery: A review

“…NCDs with photosensitizer property, illuminate visible light by using molecular oxygen to produce microbial reactive oxygen species (ROS).These ROS react non-specifically with viral or cell component generating substantial damage and inactivate wide range of microbes such as parasites, fungi, viral and bacteria. Hence, microbes which exhibit resistance to antibiotics are eventually inactivated similarly as their drug susceptible counterparts and cause nonspecific damage to ROS, which means resistance towards NCDs are unlikely to happen [ 84 ]. Devi et al found that NCDs of Aloe vera extract are good antibacterial agent against Staphylococcus aureus and Escherichia coli ( E.coli ) [ 85 ].The Aloe vera extract NCDs demonstrated bright blue luminescence under UV light and a quantum yield of 12.3 %.The antimicrobial actions can be further subcategorized into antiviral, antibacterial and antifungal activities.…”

“…Therefore, to overcome such situation inactivation of microbial growth via photodynamic therapy is promising. CDs utilizing green approach for synthesis are reported to be beneficial because they are found abundantly, no chromatographic purifications, economical, small size, biocompatible, scalable photosentizing property and multicolour emissive properties [ 84 ]. In this context, Bhamore et al found that the multicolor emissive NCDs prepared from Manilkara zapota fruit were promising imaging agents for bacterial cells of E.coli , Fomitopsis sp and Aspergillus aculeatus because of their ultra-small size as well as biocompatibility.…”

Quaternized carbon quantum dots with broad-spectrum antibacterial activity for treatment of wounds infected with mixed bacteria

“…Compared with the reported representative antibacterial carbon nanomaterials (Supplementary Table 6) 6,24,30,33,42,[52][53][54][55] , the mechanism of antibacterial action of the as-synthesized CQDs in this work provided a new way of thinking for studying the antibacterial mechanism of CQDs with broad-spectrum antibacterial activities. This study provides a feasible basis for the research and development of new antibiotics and the application of CQDs in the eld of antibiotics.…”

“…In more recent study, various nanomaterials have gradually emerged as excellent substitutes for antimicrobial agents, and have been widely explored for a broad range of bacterial infections via the photodynamic effect or/and photothermal ability [5][6][7] . Compared with reported nanomaterials, carbon nanomaterials (e.g.…”

“…Carbon quantum dots (CQDs), especially hetero-element doped CQDs with particle size of less than 10 nm, stand out in the eld of antibacterial research due to their advantageous properties including nontoxic nature, photostability, versatility in surface functionality for desired microbial adhesion and interactions, and their production from abundant and inexpensive precursors for extremely broad and low to ultralow cost applications [11][12][13][14][15][16] . At present, the mechanism of action of CQDs against bacteria mainly focuses on the three aspects of directly producing reactive oxygen species (ROS), such as superoxide (•O 2 − ) and hydroxyl radical (•OH) 17,18 , producing ROS assisted by photoactivation or other compound 6,[19][20][21] and damaging the cell membrane caused by the insertion of surface controlled CQDs through electrostatic interaction and/or hydrophobic interaction [22][23][24] . However, the above mechanism cannot further explain the signaling pathway of antibacterial CQDs against bacteria at the molecular level and there has been a lack of in-depth understanding of the interaction between such CQDs and bacteria.…”