The snow samples waste tobacco leaves-derived carbon dots for broad-spectrum and sensitive extraction of organophosphate esters

The increasing organophosphate esters (OPEs) consumption poses a significant threat to human well-being. The OPEs’ sample pretreatment is often challenging due to their distinct physical and chemical properties. Herein, carbon quantum dots derived from waste tobacco leaves (WTL-CQDs) were synthesized using a one-step hydrothermal method and employed as solid-phase microextraction (SPME) fiber coating for OPEs extraction. Coated fibers exhibited a broad-spectrum and sensitive performance for OPE extraction due to strong hydrogen bonds between amino and hydroxyl groups on WTL-CQDs and P = O groups in OPEs. The density functional theory (DFT) calculations revealed that the TD-CQDs binding energy and three alkyl, halogenated and aromatic substituted OPEs is −16 ∼ -18 kJ/mol. When coupled with a gas chromatography-flame photometric detector (GC-FPD), the developed method demonstrated a wide linear range (2–2000 ng/L) and low detection limits (0.01–20 ng/L). The proposed technique effectively detected trace OPEs in real snow meltwater samples.