title: Chemiluminescent detect of E. coli O157:H7 using immunological method based on magnetic nanoparticles.
abstract: The system of chemiluminescent magnetic enzyme-linked immunoassay was developed. E. coli O157:H7 was sandwiched between rabbits anti-E. coli O157:H7 polyclonal antibody-coated magnetic nanoparticles (immunomagnetic nanoparticles or IMNPs) and mouse anti-E. coli O157:H7 monoclonal antibody. Commercial alkaline phosphatase conjugated horse anti-mouse immunoglobulin (ALP-Ab) was used to bind with the monoclonal antibody, finally the chemiluminescent signals were detected by adding 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl-1,2-dioxetane (AMPPD) which was the substrate reagent of ALP. Different solvents of AMPPD were compared to get an optimal chemiluminescent signal. The effects of sodium borohydride and glycine on blocking the aldehyde groups of IMNPs were compared either, and the specificity and sensitivity of this system for detecting E. coli O157:H7 were researched. The results indicated that Tris buffer was the best solvent of AMPPD, sodium borohydride was better than glycine in blocking IMNPs, and this method was of good specificity when using E. coli Top 10F' and Vibrio cholera as negative controls. The detection limit was 10(3) cells mL(-1) when the antigen solution was 1 mL, and the procedure duration was about 3 h.
authors.affiliation: State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096, China.
authors.forename: Zhiyang
authors.initials: Z
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: He
authors.forename: Nongyue
authors.initials: N
authors.lastname: He
authors.forename: Zhiyang
authors.initials: Z
authors.lastname: Shi
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Hongna
authors.initials: H
authors.lastname: Liu
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Li
authors.forename: Yabin
authors.initials: Y
authors.lastname: Dai
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D019453:Escherichia coli O157 / Q000276:immunology / Q000302:isolation & purification*; D049449:Luminescence; D008280:Magnetics; D053758:Nanoparticles
chemical_list: D000911:Antibodies, Monoclonal