Hydrothermal synthesis of nitrogen-doped carbon dots as a sensitive fluorescent probe for the rapid, selective determination of Hg²⁺

ABSTRACT

In the present work, a green synthetic method for producing nitrogen-doped carbon dots (NCDs) by using ammonium citrate and urea is introduced. The obtained NCDs were characterised by transmission electron microscopy, Fourier transform infrared spectra, UV–vis absorption and fluorescence spectra. The results showed that the prepared NCDs were spherical with a size of about 3.5 nm, emitting strong and stable blue fluorescence when excited at 352 nm. It was noting that the NCDs enable sensitive and selective determination of Hg²⁺ in tap water with a linear range of 0.01–5 mg L⁻¹ based on a possible charge transfer process. The detection limit was 9.4 µg L⁻¹.

KEYWORDS:

• Hydrothermal synthesis
• nitrogen-doped carbon dots
• ammonium citrate
• urea
• Hg²⁺

Acknowledgment

The authors gratefully acknowledge the support for this work from Shanxi Scholarship Council of China: [Grant Number 2015-001].

Disclosure statement

No potential conflict of interest was reported by the authors.

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Funding

This work was supported by the Shanxi Scholarship Council of China [Grant Number 2015-001].