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

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 mu g L-1.