A green synthesis of highly luminescent carbon dots from itaconic acid and their application as an efficient sensor for Fe3+ ions in aqueous medium

The green synthesis of carbon dots (CDs) is one of the hot research areas in the present-day context. We have synthesized highly luminescent nitrogen-doped CDs (N-CDs) in a green way that can be adopted for the large-scale production of luminescent N-CDs. The aqueous solution of N-CDs possesses high colloidal and luminescence stability under various environments. We have demonstrated the N-CDs as a sensitive and selective fluorescence sensor for the determination of Fe3+ ions, which are a well-known environmental pollutant. We have achieved a limit of detection (LOD) of about 96 nM, which is much lower than most of the previously reported CD-based Fe3+ sensors. Complexation between the oxygen functionalities of N-CDs and Fe3+ followed by photoinduced electron transfer from N-CDs to Fe3+ ions is found to be the most probable mechanism for the observed sensing behavior.