title: Preparation of SiO2/polymethyl methacrylate/Fe3O4 nanoparticles and its application in detecting E. coli O157:H7 using chemiluminescent immunological method.
abstract: This paper described that Fe3O4 nanoparticles were encapsulated with methyl methacrylate (MMA) using linolenic acid (LA) as a crosslinking agent, after which the resulting polymethyl methacrylate (PMMA) embed Fe3O4 nanoparticles (PMMA/Fe3O4) were coated with silica, forming SiO2/ (PMMA/Fe3O4) core-shell structure particles. Then these magnetic nanoparticles (MNPs) were applied in the developed system of chemiluminescent magnetic enzyme-linked immunoassay. E. coli O157:H7 was sandwiched between rabbits anti-E. coli O157:H7 polyclonal antibody-coated magnetite nanoparticles (immunomagnetic nanoparticles or IMNPs) and mouse anti-E. coli O157:H7 monoclonal antibody (E. coli O157-McAb). Commercial alkaline phosphatase conjugated horse anti-mouse immunoglobulin (ALP-Ab) was used to bond 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. The specificity and sensitivity of this system for detecting E. coli O157:H7 were researched. The results indicated that 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: 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: Zhifei
authors.initials: Z
authors.lastname: Wang
authors.forename: Nongyue
authors.initials: N
authors.lastname: He
mesh_terms: D001681:Biological Assay / Q000379:methods; D015169:Colony Count, Microbial / Q000379:methods; D003460:Crystallization / Q000379:methods; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005290:Ferric Compounds / Q000737:chemistry*; D018189:Immunomagnetic Separation / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005290:Ferric Compounds; D046911:Macromolecular Substances; C000499:ferric oxide; D012822:Silicon Dioxide; D019904:Polymethyl Methacrylate