Antibacterial agent based on modification of () extract into CQDs@ has been successfully synthesized and applied against and . plants were obtained from Buton Island, Southeast Sulawesi-Indonesia, and used as precursors for Carbon Quantum Dots (CQDs). In the synthesis, the dried leaves of were macerated, and then the filtrate was modified hydrothermally in a Teflon-lined stainless steel autoclave. The modification results produce nano-sized CQDs@ particles. The PSA test confirmed this, which described the CQDs@ particle size as 57.0 nm. The results of UV-Vis spectroscopy tests illustrate that the CQDs@ molecules experience π → π* and n → π* electronic transitions at a wavelength of 367 nm. Meanwhile, in the FTIR spectroscopy test, stretching vibrations from the functional groups -OH, C-H, C=O, C-O, and the benzene ring were observed at wave numbers 3415.93 cm, 2976.16 cm, 1641.42 cm, 1274.95 cm, and 692.44 cm, respectively. Based on the antibacterial activity test, it is known that CQDs@ has high inhibitory activity against and . The resulting inhibition diameters are 15.82 mm and 11.24 mm, respectively. This high inhibitory diameter further illustrates the potential of CQDs@ for its further application as an antibacterial material in the future.