Sustainable fabrication of N-doped carbon quantum dots and their applications in fluorescent inks, Fe (III) detection and fluorescent films

In this work, the highly fluorescent N-doped carbon quantum dots (CQDs) were successfully synthesized via a simple hydrothermal method by using garlic skins (GSs) as the sole carbon source. The resultant N-doped CQDs with excitation-dependent emission demonstrates remarkable quantum yield of ~9% and superior fluorescence stability. Their strong cyan-emission character upon irradiation with UV light (365 nm) reveals their huge po-tential in anticounterfeit field as the fluorescent ink. Owing to the fluorescence quenching resulted from the tightly chelating of Fe3+ to the surface of N-doped CQDs, the CQDs can be applied a functional sensor for the detection of Fe3+, and the limit of detection is estimated as 4.44 mu M. Furthermore, the CQDs is dispersed into poly (vinyl alcohol) (PVA) matrix to make PVA/CQDs composite film. The unique optical properties of CQDs are inherited by the PVA/CQDs film, giving intensive cyan fluorescence and high visible transparency, as well as nearly 100% UV-blocking ratio in the UV region.

Automated summary

In this study, highly fluorescent N-doped carbon quantum dots were synthesized using garlic skins as a carbon source. These quantum dots demonstrated remarkable fluorescence stability and potential use in the field of anticounterfeit. Additionally, they were applied as a functional sensor for detecting Fe3+ and incorporated into a PVA matrix to create a composite film with unique optical properties.