Abstract:To establish a highly sensitive and specific method for the rapid detection of lead ions （Pb2+） in food samples，a hydrophobic carbon dot-ionic liquid dispersion system was synthesized by thermal decomposition of a mixed dithizone-functionalized ionic liquid in a sealed vessel at 210 ℃ for 8 h. The resulting carbon dots served as both luminescent and recognition elements，while the ionic liquid acted as both an enrichment solvent and a recognition element. Under 365 nm ultraviolet light，the system emitted bright red fluorescence. The hydrophobic carbon dot-ion liquid dispersion system，functioning as a highly sensitive fluorescent probe，binds to Pb2+ ions in the sample，resulting in fluorescence quenching. For Pb2+ concentrations in the range of 0.1-10.0 ng/mL，the fluorescence intensity showed an inverse relationship with the Pb2+ concentration. Under optimized conditions （pH6.0±1.0，reaction time 1 min），Pb2+ could be detected semi-quantitatively by visual color comparison or accurately quantified using a fluorescence spectrophotometer. The method demonstrated a recovery rate of 91.67%-99.24%，relative standard deviation of 1.69%-2.31%，and a detection limit of 0.1 ng/mL.The carbon dot fluorescent probe system exhibited hydrophobicity and specific enrichment capability for the target Pb2+. This rapid detection method could serve as a reference for large-scale screening and detection of Pb2+ in various sample types.