A novel coumarin derivative-modified cellulose fluorescent probe for selective and sensitive detection of CN− in food samples

In this work, a novel coumarin derivative-modified cellulose acetate (DCB-CA) was synthesized as a fluorescent probe for highly selective and sensitive determination of CN- in food samples. The DCB-CA was synthesized by using CA as a skeleton, and the coumarin derivative as the fluorophore. The DCB-CA obtained was characterized by different methods including FTIR, SEM, 1H-NMR, TGA and UV-vis spectroscopy. The DCB-CA exhibited a significant "turn-off" fluorescence response to CN-, accompanied by a distinct fluorescence color change from bright yellow to colorless. The detection limit of CN- using DCB-CA was calculated to be 5.8 × 10-7 M, which was much lower than the threshold limit of CN- recommended by the World Health Organization (1.9 × 10-6 M). Because of the favorable solubility and processability of the CA, the DCB-CA was easily processed into different fluorescent materials including fluorescent films and coatings. The fluorescent film obtained was also applied to the selective detection of CN-. Furthermore, the DCB-CA was successfully applied to determine CN- in food samples.