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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Characterization and Interventions for Foodborne Pathogens » Research » Publications at this Location » Publication #367748
Research Project: Advanced Development of Innovative Technologies and Systematic Approaches to Foodborne Hazard Detection and Characterization for Improving Food Safety

Location: Characterization and Interventions for Foodborne Pathogens

Title: Plasmonic enhancement in lateral flow sensors for improved sensing of E. coli O157:H7

Author
item REN, WEN - Purdue University
item BALLOU, DEXTER - University Of Illinois
item FITZGERALD, RYAN - University Of Illinois
item IRUDAYARAJ, JOSEPH - University Of Illinois

Submitted to: Biosensors and Bioelectronics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2018
Publication Date: 11/1/2018
Citation: Ren, W., Ballou, D.R., Fitzgerald, R., Irudayaraj, J. 2018. Plasmonic enhancement in lateral flow sensors for improved sensing of E. coli O157:H7. Biosensors and Bioelectronics. 126:324-331. https://doi.org/10.1016/j.bios.2018.10.066.
DOI: https://doi.org/10.1016/j.bios.2018.10.066

Interpretive Summary: Lateral flow immunoassay (LFIA) diagnostic test strips, of which home pregnancy tests are the best known example, are used for rapid and inexpensive detection of of foodborne bacterial pathogens. Unfortunatley LFIAs are not very sensitive. In this study we develop a modification of the LFIA, a plasmonic enhanced lateral flowsensor (pLFS), that employs gold nanoparticles and a specialized chmeical delivery system to improve the color-generating signal. A pLFS method was developed and tested for the detection of the harmful foodborne E. coli O157:H7 bacteria. Compared with the reported conventional LFIA, the pLFS demonstrated more than 1000 times improvement in sensitivity. The pLFS could detect a very low number (100 bacterial cells per mL) of E. coli O157:H7 in buffer and slightly more (600 bacterial colonies per ml) in liquid food systems. The novel modified pLFS may be applied to simple and rapid onsite detection of harmful bacteria in low numbers in a user friendly format.

Technical Abstract: We propose a plasmonic enhanced lateral flow sensor (pLFS) concept with an enhanced colorimetric signal by utilizing liposome encapsulating reagent to trigger the aggregation of gold nanoparticles (GNPs). Our signal enhancement strategy incorporates the simplicity of lateral flow immunoassays (LFIA) utilizing plasmonic enhancement. The conceptualized hybrid pLFS for onsite rapid detection of pathogens in low numbers in a user friendly format requiring simple steps is the first step in the translation of plasmonic enhancement sensing to a practical regime. The pLFS was carried out with a biotinylated liposome label ruptured to release branched polyethylenimine (BPEI) to trigger the aggregation of GNPs for colorimetric signal generation. BPEI has multiple amino groups and more positive charges in PBS buffer, therefore few of the BPEI groups could induce the aggregation of GNPs, resulting in an enhanced colorimetric signal to detect E. coli O157:H7. Compared with the reported conventional LFIA, the proposed pLFS demonstrated more than 1000-fold improvement in sensitivity. The pLFS could detect as low as 100 CFU/ml of E. coli O157:H7 in buffer and 600 CFU/ml E. coli O157:H7 in liquid food systems.