Simple and green approach for photoluminescent carbon dots prepared via Faba bean seeds as a luminescent probe for determination of Hg⁺ ions and cell imaging

Abstract

In this research, for the first time, a dedicated sensor was designed to detect Hg⁺ ions using photoluminescent carbon dots (CDs). Due to preferred green synthesis of CDs from bio‐resources, carbohydrate‐rich faba bean seeds as a potential carbon precursors were applied to the synthesis of CDs. In the absence of substances such as acid or base and any other additives, the CDs were prepared from the faba bean seeds by the hydrothermal method in aqueous solution. The synthesized CDs exhibited maximum emission intensity at 387 nm, when excited at 310 nm and their luminescence quantum yield was calculated about 5.94%. Then, the fluorescence emission of CDs was examined at the presence of the different metal ions. Results reveled that the CDs have good selectivity toward the Hg⁺ ions, so that the fluorescence emission is significantly changed in the presence of this ions with the detection limit (LOD) as low as 0.35 μM. Furthermore, since of very low cytotoxicity, these CDs can be applied for cell imaging.