Chitosan-derived N-doped carbon dots for fluorescent determination of nitrite and bacteria imaging

N-doped carbon dots (N-CDs) were successfully synthesized via simple one-step hydrothermal carbonization using chitosan as carbon and nitrogen sources. The obtained N-CDs contained a variety of functional groups on the NCDs surface, and exhibited excitation-independent behavior and strong blue fluorescence with a relatively higher fluorescence quantum yield (QY = 35%). It also presented excellent water solubility, resistance to pH change, high ion strength and UV irradiation. Since the fluorescence of the N-CDs could be selectively quenched by NO2-, they could act as a fluorescent sensor for the determination of NO2- in real tap water and lake water samples with a wide linear range (1-500 mu M) and low detection limit (0.1 mu M). They could also be used for bacterial imaging as multicolor fluorescent probes. The results indicated that N-CDs could be a promising candidate material for biomedical applications. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

N-doped carbon dots (N-CDs) were successfully synthesized and showed promising potential in fluorescence sensing and bacterial imaging applications.