Graphene quantum dots enhanced with gold nanoparticles for advanced antibacterial applications

Abstract

In the era of antibiotic resistance, exploring novel nanomaterials offers a promising avenue for combating infections. This study investigates the antibacterial effects of graphene quantum dots (GQDs) combined with gold nanoparticles, synthesized in situ via gamma irradiation of GQDs with chloroauric acid and isopropyl alcohol at doses of 1, 5, 10, and 20 kGy. The composites were analyzed using several characterization methods, including photoluminescence and infrared spectroscopy, dynamic light scattering, zeta potential measurements, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Inductively coupled plasma optical emission spectrometry analysis confirmed the presence of gold in all samples, with the highest concentration of 11.14 μg/mL. Hemolytic assays confirmed excellent biocompatibility with hemolysis below 2 %, while MTT assays revealed that cell viability exceeded 80 % for most samples, confirming their non-toxic nature. The findings showed that these materials have antibacterial activity against the MRSA strain. These results demonstrate that gold nanoparticles significantly contribute to the antibacterial properties of GQDs, indicating their potential for biomedical applications.