Green carbon dots from Livistona chinensis leaves as a platform for lead(II) sensing and antibacterial activity against multidrug-resistant bacterial strains

This study was aimed at synthesizing carbon dots (CDs) from the leaves of a medicinal plant called Livistona chinensis; characterize them, explore their use in lead(II) sensing, and evaluate their antibacterial properties against multidrug-resistant bacterial strains. Green CDs were synthesized by following bottom-up hydrothermal method and the synthesis was confirmed by ultraviolet (UV)-visible spectroscopy. To determine their attributes, different analytical methods, such as X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier-transform-infrared (FTIR), were used. From the results, the synthesized CDs exhibited sensitive Pb2+ detection through UV–visible absorbance modulation arising from metal–surface complexation, achieving low detection and quantification limits, in water samples, with 0.5 and 1.8 μM as limits of detection and quantification, respectively. The CDs also showed antibacterial activities against the tested drug resistant Gram-positive and Gram-negative bacterial strains such as Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Comparatively, the greatest inhibition zone was 17.1 mm, against Pseudomonas aeruginosa bacterial strain. Based on the results, the synthesized green carbon dots were concluded to have good sensitivity for detecting Pb2+ in water and contain good antibacterial properties against the tested bacterial strains.