title: A novel enzyme-linked immunosorbent assay for detection of Escherichia coli O157:H7 using immunomagnetic and beacon gold nanoparticles.
abstract: This paper presents a functional nanoparticle-enhanced enzyme-linked immunosorbent assay (FNP-ELISA) for detection of enterohemorrhagic Escherichia coli (EHEC) O157:H7. Immunomagnetic nanoparticles (IMMPs) conjugated with monoclonal anti-O157:H7 antibody were used to capture E. coli O157:H7. Beacon gold nanoparticles (B-GNPs) coated with polyclonal anti-O157:H7 and biotin single-stranded DNA (B-DNA) were then subjective to immunoreaction with E. coli O157:H7, which was followed by streptavidin-horseradish peroxidase (Strep-HRP) conjugated with B-GNPs based on a biotin-avidin system. The solutions containing E. coli O157:H7, IMMPs, B-GNPs, and Strep-HRP were collected for detecting color change. The signal was significantly amplified with detection limits of 68 CFU mL(-1) in PBS and 6.8 × 10(2) to 6.8 × 10(3) CFU mL(-1) in the food samples. The FNP-ELISA method developed in this study was two orders of magnitude more sensitive than immunomagnetic separation ELISA (IMS-ELISA) and four orders of magnitude more sensitive than C-ELISA. The entire detection process of E. coli O157:H7 lasted only 3 h, and thus FNP-ELISA is considered as a time-saving method.
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Nannan
authors.initials: N
authors.lastname: Hou
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Min
authors.initials: M
authors.lastname: Jin
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Qiu
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Tianjin Institute of Health and Environmental Medicine, Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin 300050, China.
authors.forename: Junwen
authors.initials: J
authors.lastname: Li
keywords: Beacon gold nanoparticles; ELISA; Escherichia coli O157:H7; Immunomagnetic nanoparticles