Heteroatom doped carbon dots from green sources as metal ion sensor and as fluorescent ink

Abstract

In this study, novel eco-friendly nitrogen-doped carbon dots (NCDs) were prepared via a green, efficient, and one-pot synthesis method from Sida cordifolia root as the carbon source and triethylene tetraamine as the nitrogen source for the detection of metal ions. The amorphous, nanosized carbon dots with 17.8 % quantum yield exhibited exceptional stability towards different experimental conditions. These NCDs acted as a nanoprobe for the sensing of Co(II) and Cu(II) via fluorescence and electrochemical techniques, respectively. These blue fluorescent carbon dots detects Co(II) with a detection limit as low as 0.11 μM and Cu(II) with 0.03 nM. The inner filter effect (IFE) acted as the primary fluorescence quenching mechanism. Also, the developed sensor could detect metal ions in different water samples. Moreover, NCDs were used as fluorescent security ink for writing and drawing. The findings of this study open up a new platform for the effective and reliable sensing of metal ions.