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P3-179 An Electrochemical Aptasensor for Rapid Detection of Salmonella Typhimurium in Poultry Based on the Bifunctional Magnetic Nanocomposites

Wednesday, July 12, 2017
Exhibit Hall (Tampa Convention Center)
Ronghui Wang , University of Arkansas, Department of Biological and Agricultural Engineering , Fayetteville , AR
Meng Xu , University of Arkansas , Fayetteville , AR
Jianhan Lin , China Agricultural University , Beijing , China
Ming Liao , South China Agricultural University , Guangzhou , China
Michael Kidd , University of Arkansas , Fayetteville , AR
Yanbin Li , University of Arkansas, Department of Biological and Agricultural Engineering , Fayetteville , AR
Introduction:  Salmonella Typhimurium is one of the most commonly identified foodborne pathogens for humans and animals, which pose a threat to human health and cause substantial economic cost to society. The development of a rapid, specific and sensitive method to detect S. Typhimurium is urgently needed for ensuring food safety.

Purpose:  The objective of the present study was to develop an electrochemical aptasensor for rapid detection of S. Typhimurium, based on the magnetic bifunctional polydopamine (PDA) polymeric nanocomposites (PMNCs).

Methods:  The core-shell magnetic beads (MBs)-glucose oxidase (GOx)@PDA PMNCs were first synthesized as the primary vehicle to support the further functionalization and to isolate and concentrate the target bacteria. Gold nanoparticles (AuNPs) were biochemically synthesized on the surface of PMNCs to adsorb anti-Salmonella aptamers. The 3, 3’-Dithiodipropionic acid di(N-hydroxysuccinimide ester (DTSP) was used to cross-link the AuNPs and the aptamers. The final product of the aptamers/GOxext/AuNPs/MBs-GOx@PDA PMNCs can carry the target bacteria and be magnetically attracted to the surface of the screen-printed interdigitated electrode (SP-IDME) for measurement. The redox probe containing glucose recognized the current changes caused by the attachment of S. Typhimurium cells.

Results:  The synthesized aptamers/GOxext/AuNPs/MBs-GOx@PDA PMNCs was demonstrated to be able to generate current responses that were linearly related to the log concentration of S. Typhimurium. The detection limit of the developed aptasensor was 96 cfu S. Typhimurium/ml in pure culture, within one hour, without pre-enrichment procedures. Ongoing research will focus on the validation of the aptasensor using poultry samples.

Significance:  The outcome of this study provided a bifunctional PMNCs to improve the sensitivity of the aptasensor due to the higher loading efficiency of biomaterials through PNMCs.

Back to: Poster Session 3 – Low-water Activity Foods, Packaging, Produce, Microbial Food Spoilage, Antimicrobials, Laboratory and Detection Methods, Water
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