Carbon quantum dots derived from camphor tree leaves biomass as a highly selective probe for Fe³⁺ sensing

Carbon quantum dots (CQDs), as a novel category of zero-dimensional fluorescent materials, have garnered significant interest because of their distinctive optical characteristics, low toxicity, and easy surface modification. However, most techniques used to manufacture CQDs involve costly raw materials, intricate production processes, or hazardous chemicals. In this study, innovatively, low-cost, renewable, and green biomass raw material, camphor tree waste leaves, were employed to prepare CQDs through a simple one-step hydrothermal approach under relatively mild conditions. The results indicate that the prepared CQDs had a size of around 1.6 nm and a thickness of one to six layers of graphene. They can function as a reliable fluorescent probe for detecting Fe³⁺, exhibiting a limit of detection (LOD) of 2.03 μM. The full utilization of renewable resources, combined with relatively simple hydrothermal processing, enables the environmentally friendly and economical production of CQDs that have broad prospects for metal ion sensing applications.