title: In-situ immuno-gold nanoparticle network ELISA biosensors for pathogen detection.
abstract: Food poisoning microorganisms that contaminate food products and compromise food safety and security have been considered a major health threat and a serious concern for food producers and processors. Developing sensor technologies that are rapid for sensitive and selective detection and quantification of pathogens is a high priority for scientists in academia, state and federal research institutes, and industries. In this work we propose an in-situ immuno-AuNP network-based ELISA biosensor integrated with a sample concentration step based on immuno-magnetic separation to detect pathogenic microorganisms with high sensitivity. The sensor system was optimized by the specific formation of immuno-AuNP network onto the antigenic site present at the outer membrane surface of bacteria and the analytical concept was validated by a microtiter immunoassay. The in-situ network biosensor was able to detect pathogens at extremely low numbers: 3 cells/mL of Escherichia coli O157:H7 and Salmonella typhimurium in buffer and 3 CFU/mL of E. coli O157:H7 and 15CFU/mL of S. typhimurium in real sample conditions within 2h of inoculation. The ability to monitor target bacteria with improved analytical sensitivity compared to the current techniques presents a unique opportunity for routine monitoring to improve the safety of foods.
authors.affiliation: Bindley Bioscience and Birck Nanotechnology Center, Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN 47907, United States.
authors.forename: Il-Hoon
authors.initials: IH
authors.lastname: Cho
authors.forename: Joseph
authors.initials: J
authors.lastname: Irudayaraj
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004797:Enzyme-Linked Immunosorbent Assay; D019453:Escherichia coli O157 / Q000502:physiology; D005516:Food Microbiology / Q000379:methods*; D059022:Food Safety / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D053758:Nanoparticles / Q000737:chemistry*; D012486:Salmonella typhimurium / Q000502:physiology; D012680:Sensitivity and Specificity
chemical_list: D006046:Gold