title: Rapid pathogen detection by lateral-flow immunochromatographic assay with gold nanoparticle-assisted enzyme signal amplification.
abstract: To date most LF-ICA format for pathogen detection is based on generating color signals from gold nanoparticle (AuNP) tracers that are perceivable by naked eye but often these methods exhibit sensitivity lower than those associated with the conventional enzyme-based immunological methods or mandated by the regulatory guidelines. By developing AuNP avidin-biotin constructs in which a number of enzymes can be labeled we report on an enhanced LF-ICA system to detect pathogens at very low levels. With this approach we show that as low as 100 CFU/mL of Escherichia coli O157:H7 can be detected, indicating that the limit of detection can be increased by about 1000-fold due to our signal amplification approach. In addition, extensive cross-reactivity experiments were conducted (19 different organisms were used) to test and successfully validate the specificity of the assay. Semi-quantitative analysis can be performed using signal intensities which were correlated with the target pathogen concentrations for calibration by image processing.
authors.affiliation: Bindley Bioscience and Birck Nanotechnology Center, Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN 47907, United States; Department of Biomedical Laboratory Science, College of Health Science, Eulji University, Seongnam 461-713, Republic of Korea.
authors.forename: Il-Hoon
authors.initials: IH
authors.lastname: Cho
authors.affiliation: Department of Food Science, Purdue University, West Lafayette, IN 47907, United States.
authors.forename: Arun
authors.initials: A
authors.lastname: Bhunia
authors.affiliation: Bindley Bioscience and Birck Nanotechnology Center, Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN 47907, United States. Electronic address: josephi@purdue.edu.
authors.forename: Joseph
authors.initials: J
authors.lastname: Irudayaraj
mesh_terms: D002846:Chromatography, Affinity; D019453:Escherichia coli O157 / Q000502:physiology*; D005516:Food Microbiology / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D006046:Gold
keywords: Enzyme immunoassay; Lateral-flow immunochromatography; Pathogen detection; Rapid detection; Signal enhancement