Green preparation of carbon dots by Jinhua bergamot for sensitive and selective fluorescent detection of Hg2+ and Fe3+

Green, low-cost, and water-soluble fluorescent carbon dots were prepared under hydrothermal conditions, with a plant of Jinhua bergamot as a carbon source. The as-synthesized C-dots have better stability and relatively high photoluminescence with a quantum yield of 50.78%, along with the fluorescence lifetime of ca. 3.84   ns. Their photoluminescence can be significantly quenched by simply using the buffer solution of HAC–NaAC for Hg 2+ and Tris–HCl for Fe 3+ . Based on this, we explored for selective detection of Hg 2+ and Fe 3+ with high selectivity, fast response, low cost, and broad linear ranges of 0.01–100   μM for Hg 2+ and 0.025–100   μM for Fe 3+ , as well as low detection limits of 5.5   nM (Hg 2+ ) and 0.075   μM (Fe 3+ ) (S/N   =   3).