title: Dual gold nanoparticle lateflow immunoassay for sensitive detection of Escherichia coli O157:H7.
abstract: Two patterns of signal amplification lateral flow immunoassay (LFIA), which used anti-mouse secondary antibody-linked gold nanoparticle (AuNP) for dual AuNP-LFIA were developed. Escherichia coli O157:H7 was selected as the model analyte. In the signal amplification direct LFIA method, anti-mouse secondary antibody-linked AuNP (anti-mouse-Ab-AuNP) was mixed with sample solution in an ELISA well, after which it was added to LFIA, which already contained anti-E. coli O157:H7 monoclonal antibody-AuNP (anti-E. coli O157:H7-mAb-AuNP) dispersed in the conjugate pad. Polyclonal antibody was the test line, and anti-mouse secondary antibody was the control line in nitrocellulose (NC) membrane. In the signal amplification indirect LFIA method, anti-mouse-Ab-AuNP was mixed with sample solution and anti-E. coli O157:H7-mAb-AuNP complex in ELISA well, creating a dual AuNP complex. This complex was added to LFIA, which had a polyclonal antibody as the test line and secondary antibody as the control line in NC membrane. The detection sensitivity of both LFIAs improved 100-fold and reached 1.14×10(3) CFU mL(-1). The 28 nm and 45 nm AuNPs were demonstrated to be the optimal dual AuNP pairs. Signal amplification LFIA was perfectly applied to the detection of milk samples with E. coli O157:H7 via naked eye observation.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Zhibiao
authors.initials: Z
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Daofeng
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Shuying
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China; Department of Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China; Department of Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China; Department of Science and Technology, Nanchang University, Nanchang, China.
authors.forename: Hengyi
authors.initials: H
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China. Electronic address: talktolaiwh@163.com.
authors.forename: Weihua
authors.initials: W
authors.lastname: Lai
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D004867:Equipment Design; D004927:Escherichia coli Infections / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005516:Food Microbiology / Q000295:instrumentation; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008892:Milk / Q000382:microbiology*
chemical_list: D006046:Gold
keywords: Dual lateral flow immunoassay; E. coli O157:H7; Signal amplification