High quantum yield nitrogen doped carbon dots for Ag+ sensing and bioimaging.

• A simple method is utilized to produce N-doped carbon dots (N CDs) from o-aminophenol and ethylenediamine. • The N CDs possess quantum yield up to 38.4%. • Owing to the highly sensitive response to Ag+, the prepared N CDs can be developed as an effective sensing platform. • The N CDs are also used in bioimaging. N-doped carbon dots (N CDs) with green fluorescence is developed by the hydrothermal reaction with o-aminophenol and ethylenediamine as carbon and nitrogen sources, and the quantum yield (QY) is 38.4%. The N CDs are characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible absorption spectroscopy (UV–vis) and fluorescence spectroscopy. The results show that N CDs have good fluorescence properties and stability, and the N CDs are further utilized as a sensor for Ag+ via the static quenching effect (SQE) (λ ex =430 nm, λ em =510 nm). The linear range of Ag+ is 30–210 µmol/L with a limit of detection (LOD) of 4.7 µmol/L (S/ N = 3). On this basis, we quantitatively detect Ag+ in real samples. Furthermore, due to the excellent fluorescence performance, the N CDs are found to be an effective tool for Ag+ sensing in bioimaging. Herein, green-emission fluorescent N-doped carbon dots (N CDs) are developed by the hydrothermal reaction of o-aminophenol and ethylenediamine, and the quantum yield (QY) is 38.4%. The N CDs are utilized as a sensor for Ag+, and the linear range is 30–210 µM with a limit of detection (LOD) of 4.7 µM (S/ N = 3). On the other hand, the N CDs are further applied to biological imaging, constructing the fluorescence analysis method of Ag+ in biological samples. [Display omitted] [ABSTRACT FROM AUTHOR]