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Updated: Mar 16, 2026
Foodborne Pathogen Screening Using Magneto-fluorescent Nanosensor: Rapid Detection of E. Coli O157:H7
Published on: September 17, 2017
One-step multiplexed detection of foodborne pathogens: Combining a quantum dot-mediated reverse assaying strategy and
Binfeng Yin1, Yu Wang2, Mingling Dong3
1Beijing Engineering Research Center for BioNanotechnology and CAS Key Lab for Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for NanoScience and Technology, Beijing 100190, China; School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749, South Korea.
Abstract:
A rapid and multiplexed immunosensor was developed based on a quantum dot (QD)-reverse assaying strategy (RAS) and immuno-magnetic beads (IMBs) for one-step and simultaneous detection of Escherichia coli O157: H7 and Salmonella. In a conventional QD-based immunosensor, the fluorescence signal of the "IMBs-target-QD" immunoconjugate is directly used as the assaying readout. However, the fluorescence signal is affected by IMBs due to light scattering and the "IMBs-target-QD" immunoconjugate needs multiple washing and re-suspension steps. To address these problems, we use the surplus QD-antibody conjugate as signal readout in the RAS, which prevents interference from the IMBs, increases the fluorescence signal, and avoids complex operations. Compared with conventional QD-based immunosensor, the sensitivity of QD-RSA immunosensor for detection of Escherichia coli O157: H7 has been improved fifty-fold, and whole analysis procedure can be finished within 1h. Therefore, this RSA strategy is promising for improving the performance of QD-based immunosensors and could greatly broaden their applications.
