A highly sensitive and reliable fluorescence immunoassay based on the fluorescence quenching(FQ)effect of quantum dots(QDs)was developed for the sensitive detection of norfloxacin(NOR)in animal-origin foods.Briefly,th...A highly sensitive and reliable fluorescence immunoassay based on the fluorescence quenching(FQ)effect of quantum dots(QDs)was developed for the sensitive detection of norfloxacin(NOR)in animal-origin foods.Briefly,the enzymatic formation of horseradish peroxidase(HRP)in conventional ELISA effectively quenched the fluorescence of QDs through inner-filter effect(IFE)and fluorescence resonance energy transfer(FRET),and then the absorption signal of conventional ELISA was transformed to fluorescent signals,resulting in a higher sensitivity for NOR detection in animal-origin foods.The detection limit of NOR in this developed method was 0.20μg L1 in standard solution,which was 12-fold more sensitive than conventional ELISA(2.50μg L1).The results of specificity analysis revealed that the proposed method could not only be used for the detection of NOR,but also for the other 9 structural analogues.The recovery rates of NOR-spiked animal-origin foods ranged from 88.11%to 108.16%,with CV values of 1.95%-18.03%.In addition,the established method had good consistency with the commercial ELISA kits and HPLC,indicating the accuracy of the developed method for the detection of NOR in real samples.In conclusion,the established fluorescence immunoassay was sensitive and facile,and could be alternatively used for the determination of NOR residues in animal-origin foods.展开更多
基金supported by Science and Technology Project of Hebei Education Department(QN2020177).
文摘A highly sensitive and reliable fluorescence immunoassay based on the fluorescence quenching(FQ)effect of quantum dots(QDs)was developed for the sensitive detection of norfloxacin(NOR)in animal-origin foods.Briefly,the enzymatic formation of horseradish peroxidase(HRP)in conventional ELISA effectively quenched the fluorescence of QDs through inner-filter effect(IFE)and fluorescence resonance energy transfer(FRET),and then the absorption signal of conventional ELISA was transformed to fluorescent signals,resulting in a higher sensitivity for NOR detection in animal-origin foods.The detection limit of NOR in this developed method was 0.20μg L1 in standard solution,which was 12-fold more sensitive than conventional ELISA(2.50μg L1).The results of specificity analysis revealed that the proposed method could not only be used for the detection of NOR,but also for the other 9 structural analogues.The recovery rates of NOR-spiked animal-origin foods ranged from 88.11%to 108.16%,with CV values of 1.95%-18.03%.In addition,the established method had good consistency with the commercial ELISA kits and HPLC,indicating the accuracy of the developed method for the detection of NOR in real samples.In conclusion,the established fluorescence immunoassay was sensitive and facile,and could be alternatively used for the determination of NOR residues in animal-origin foods.
