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Proceedings Paper

Rapid detection of Salmonella typhimurium on fresh spinach leaves using phage-immobilized magnetoelastic biosensors
Author(s): Shin Horikawa; Suiqiong Li; Yating Chai; Mi-Kyung Park; Wen Shen; James M. Barbaree; Vitaly J. Vodyanoy; Bryan A. Chin
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Paper Abstract

This paper presents an investigation into the use of magnetoelastic biosensors for the rapid detection of Salmonella typhimurium on fresh spinach leaves. The biosensors used in this investigation were comprised of a strip-shaped, goldcoated sensor platform (2 mm-long) diced from a ferromagnetic, amorphous alloy and a filamentous fd-tet phage which specifically binds with S. typhimurium. After surface blocking with bovine serum albumin, these biosensors were, without any preceding sample preparation, directly placed on wet spinach leaves inoculated with various concentrations of S. typhimurium. Upon contact with cells, the phage binds S. typhimurium to the sensor thereby increasing the total mass of the sensor. This change in mass causes a corresponding decrease in the sensor's resonant frequency. After 25 min, the sensors were collected from the leaf surface and measurements of the resonant frequency were performed immediately. The total assay time was less than 30 min. The frequency changes for measurement sensors (i.e., phageimmobilized) were found to be statistically different from those for control sensors (sensors without phage), down to 5 × 106 cells/ml. The detection limit may be improved by using smaller, micron-sized sensors that will have a higher probability of contacting Salmonella on the rough surfaces of spinach leaves.

Paper Details

Date Published: 3 June 2011
PDF: 7 pages
Proc. SPIE 8027, Sensing for Agriculture and Food Quality and Safety III, 802709 (3 June 2011); doi: 10.1117/12.883707
Show Author Affiliations
Shin Horikawa, Auburn Univ. (United States)
Suiqiong Li, Auburn Univ. (United States)
Yating Chai, Auburn Univ. (United States)
Mi-Kyung Park, Auburn Univ. (United States)
Wen Shen, Auburn Univ. (United States)
James M. Barbaree, Auburn Univ. (United States)
Vitaly J. Vodyanoy, Auburn Univ. (United States)
Bryan A. Chin, Auburn Univ. (United States)

Published in SPIE Proceedings Vol. 8027:
Sensing for Agriculture and Food Quality and Safety III
Moon S. Kim; Shu-I Tu; Kaunglin Chao, Editor(s)

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