Detection of Escherichia coli on the Ground Beef using Magnetoelastic Biosensor with Antibody Immobilized = Detection of Escherichia coli on the Ground Beef using Magnetoelastic Biosensor with Antibody Immobilized

다국어 초록 (Multilingual Abstract)

Bacterial detection methods have been developed for the direct detection of pathogens related to health hazards including Escherichia coli. Magnetoelastic biosensor (ME) has been demonstrated to be a reliable method of recognizing bacteria leading to foodborne diseases due to high sensitivity and rapid response. In this study, magnetoelastic biosensor was employed to detect E. coli on the contaminated ground beef. ME biosensor consists of a wireless magnetoelastic sensor and a surface-scanning detector. Metglas platform was used to fabricate ME sensor, sputtered with Ti first to act as an adhesion and Au to serve as a bioactive surface. In order to form bio-recognition layers on the ME sensor for antibody-antigen binding, self-assembled monolayer (SAM) technique was performed, which ensures the attachment of the antibodies to the sensor. After the antibodies were immobilized on the ME sensor, the sensor was put on the ground beef surface placed Escherichia coli suspension. Change in mass caused by the specific binding displayed change in the resonance frequencies using the surface-scanning detector. When the ME sensor attached bacteria was close enough to the detector, the increase or decrease in resonance frequencies was obtained. The focus on this study is to measure the resonance frequency changed depending on the concentration of E coli. Furthermore, this study was conducted to investigate the suitability of SAM technique with scanning electron microscopy (SEM) utilized. The frequencies of control sensors were compared to those reacted to E coli. The experimental results indicated that the frequencies decreased owing to the mass caused by reaction on the surface when concentrations of E.coli increased. This suggested that the system was capable of detecting E.coli even at low concentration rapidly.