Carbon Nanodots/Cajuput Oil Composites for Potential Antibacterial Applications

Background: We reported for the first time the preparation of carbon nanodots/ cajuput oil (C-dots/CJO) composites for potential antibacterial applications. Methods: The C-dots were synthesized from CJO distillation wastes via the low carbonization method. Then, the C-dots were mixed with CJO to obtain C-dots/CJO composites. The characteristics of the C-dots were determined using UV-Vis, PL, TRPL, FTIR, and HRTEM, whereas the C-dots/CJO composites were characterized using UV-Vis and FTIR. Results: Antibacterial properties were investigated for samples of C-dots, CJO, and C-dots/CJO with no-light, white light, and UV/violet light treatments. The C-dots produced cyan luminescence with a decay lifetime of 6.54 ns. Based on the antibacterial tests, the C-dots/CJO composites have DIZ higher than the pure C-dots. Conclusion: The C-dots/CJO composites reached the highest DIZ of 3.6 nm under white light, which was attributed to the photodynamic effect and photodisinfection of the C-dots and CJO, respectively. Hence, the C-dots/CJO composites can be potential antibacterial agents against E. coli bacteria.