Application of Carbon Dots as Antibacterial Agents: A Mini Review

Abstract
Carbon dots (CDs) are sub-10 nm carbon particles with notable photoluminescence and photoelectrochemical properties,
finding diverse applications in optoelectronics, chemistry, and medicine. Their unique physicochemical properties give rise
to antimicrobial actions, being realized through complex mechanisms. Discovering the latter was the aim of this review. The
primary interaction of CDs with negatively charged bacterial cells is ensured by electrostatic interaction with that because
of CDs’ surface positive charge. Hydrophobic forces further contribute to this interaction. Modification of CDs with different
alkyl chains enhances their antibacterial effect by balancing positive charge and hydrophobicity, facilitating membrane
penetration and causing damage to bacterial cells. Another powerful antibacterial mechanism is the ability of photoexcited
CDs to generate reactive oxygen species under visible light, effectively destroying critical biomolecules and inducing cell
death. Additionally, the photothermal conversion properties of CDs, allowing them to raise local temperatures upon nearinfrared
light excitation, result in DNA damage and protein denaturation within bacteria, forming the basis for photothermal
therapy. Following infiltration of bacterial walls and membranes, CDs can bind to DNA and RNA in bacteria and fungi
through noncovalent interactions, inducing structural changes in DNA and affecting RNA. These multifaceted mechanisms
underscore the potential of CDs as versatile antibacterial agents with applications across various biomedical fields.