Eco‐Friendly Synthesis of Sugar‐Derived Fluorescent Carbon Dots for Metal Ion Sensing, Antioxidant, and Antimicrobial Activities

Carbon dots are new zero-dimensional nanomaterials known for their unique properties, such as photoluminescence, low-cost synthesis, and biocompatibility, making them suitable for various applications. Hg²⁺ and Fe³⁺, as heavy metal ions that pose significant health and environmental risks, can be effectively detected using carbon dots due to their stable fluorescence properties and surface functional groups. Therefore, this work developed carbon dots derived from sugar (SCDs) using a simple hydrothermal method for sensing metal ions, antioxidant, and antimicrobial applications. SCDs with an 8.9 nm average size demonstrated excellent fluorescence properties and high photostability under UV illumination, visible light, high ionic strength, and different pH conditions. Additionally, SCDs exhibited antioxidant and antimicrobial abilities due to the surface interaction with cell membranes. A paper-based test strip application of SCDs showed effectiveness with low detection limits for metal ion detection. The results suggested that the as-synthesized SCDs could potentially be applied for environmental metal ion monitoring and antimicrobial use.