Simple and Green Synthesis of Boron-, Sulfur-, and Nitrogen-Co-Doped Carbon Dots as Fluorescent Probe for Selective and Sensitive Detection of Sunset Yellow

Abstract

Herein, we have reported the synthesis of boron-, sulfur-, and nitrogen-co-doped carbon dots (B/S/N-CDs) by one-step hydrothermal method using D-([Formula: see text])-maltose monohydrate, boracic acid, and thiocarbamide as the precursors. The prepared B/S/N-CDs possess good water dispersibility, excellent pH stabilities, and resistance to photobleaching. Furthermore, the transmission electron microscope image indicates that the B/S/N-CDs are homogeneously spherical and show good dispersion. Noticeably, the B/S/N-CDs show bright blue photoluminescence with a quantum yield of 8.9% in aqueous solution and can be used as a potent photoluminescent probe for selective and sensitive detection of sunset yellow (SY). Compared with other food colors, SY can dramatically quench the fluorescence of B/S/N-CDs. Meanwhile, the fluorescence intensity displays a good linear response with SY concentration in the range of 0–70[Formula: see text][Formula: see text]M ([Formula: see text]) and the detection limit is as low as 4.65[Formula: see text]nM. The B/S/N-CDs can also be applied for the detection of SY in mineral water and business drink with satisfactory recovery. Our study has demonstrated that the B/S/N-CDs may have wide application values in medical detection, environmental monitoring, and related researches.