title: One-step multiplexed detection of foodborne pathogens: Combining a quantum dot-mediated reverse assaying strategy and magnetic separation.
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.
authors: Beijing 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.
authors: Binfeng
authors: B
authors: Yin
authors: Beijing Friendship Hospital, Capital Medical University, 95,Yongan Road, Xicheng District, Beijing 100050, China; Beijing Institute for Tropical Medicine, Beijing 100050, China.
authors: Yu
authors: Y
authors: Wang
authors: Beijing 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.
authors: Mingling
authors: M
authors: Dong
authors: Analytical & Testing Center of Beijing Normal University, Beijing 100875, China.
authors: Jing
authors: J
authors: Wu
authors: Beijing 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.
authors: Bei
authors: B
authors: Ran
authors: Analytical & Testing Center of Beijing Normal University, Beijing 100875, China. Electronic address: xiemx@bnu.edu.cn.
authors: Mengxia
authors: M
authors: Xie
authors: School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749, South Korea. Electronic address: swjoo@yu.ac.kr.
authors: Sang Woo
authors: SW
authors: Joo
authors: Beijing 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. Electronic address: chenyp@nanoctr.cn.
authors: Yiping
authors: Y
authors: Chen
mesh_terms: D015373:Bacterial Typing Techniques / Q000295:instrumentation; D045424:Complex Mixtures / Q000032:analysis; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology / Q000295:instrumentation; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D008087:Listeria / Q000302:isolation & purification*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation
chemical_list: D045424:Complex Mixtures
keywords: Multiplexed detection; One-step detection; Quantum dot; Reverse assaying strategy