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One-step multiplexed detection of foodborne pathogens: Combining a quantum dot-mediated reverse assaying strategy and magnetic separation

2016; Elsevier BV; Volume: 86; Linguagem: Inglês

10.1016/j.bios.2016.07.106

1873-4235

Binfeng Yin, Yu Wang, Mingling Dong, Jing Wu, Bei Ran, Mengxia Xie, Sang Woo Joo, Yiping Chen,

SARS-CoV-2 detection and testing

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.