Photodeactivation of Pathogenic Bacteria using Photosensitizers and Graphene Quantum Dots

Photodeactivation of Pathogenic Bacteria using Photosensitizers and Graphene Quantum Dots Deactivating bacteria through photosensitizing compounds has been extensively studied and proved effective in isolated scenarios. However, these compounds are often hindered by their low singlet oxygen yield (1O2) and their bio incompatibility. Graphene quantum dots (GQDs) are an exciting new possible solution to the issues facing previously studied bacteria-deactivating substances. GQDs are single-layer thick, hexagonal lattices that have a high chemical stability and low toxicity due to their carbon structure. To synthesize GQDs, a solid state Nd:YAG pulsed laser operating at 1064 nm and 10 Hz was used to irradiate a mixture of nickel oxide and benzene. Multiple processes such as transmission electron microscopy (TEM) and nuclear magnetic resonance (NMR) were used to characterize the GQDs. Methylene blue (MB) was used as a reference as it is capable of a bacteria deactivation through high 1O2 production. However, MB was not able to accomplish this in blood due to protein binding, thus GQDs could be used to replace MB as an effective alternative for treatment of bacterial infections. Preliminary results have produced GQDs of less than 10 nm peaking around 310 nm. These promising results indicate that GQDs could be used to eliminate harmful pathogens in the body. This would be especially beneficial in a time of increasing bacterial resistance. Khomidkhodza Kholikov, Zachary Thomas, Skyler Smith, Dovletgeldi Seyitliyev, and Ali Oguz E