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dc.contributor.authorLi, Fuquan
dc.contributor.authorKosel, Jürgen
dc.date.accessioned2015-08-03T12:07:47Z
dc.date.available2015-08-03T12:07:47Z
dc.date.issued2014-09
dc.identifier.citationLi, F., & Kosel, J. (2014). An efficient biosensor made of an electromagnetic trap and a magneto-resistive sensor. Biosensors and Bioelectronics, 59, 145–150. doi:10.1016/j.bios.2014.03.035
dc.identifier.issn09565663
dc.identifier.pmid24727202
dc.identifier.doi10.1016/j.bios.2014.03.035
dc.identifier.urihttp://hdl.handle.net/10754/563722
dc.description.abstractMagneto-resistive biosensors have been found to be useful because of their high sensitivity, low cost, small size, and direct electrical output. They use super-paramagnetic beads to label a biological target and detect it via sensing the stray field. In this paper, we report a new setup for magnetic biosensors, replacing the conventional "sandwich" concept with an electromagnetic trap. We demonstrate the capability of the biosensor in the detection of E. coli. The trap is formed by a current-carrying microwire that attracts the magnetic beads into a sensing space on top of a tunnel magneto-resistive sensor. The sensor signal depends on the number of beads in the sensing space, which depends on the size of the beads. This enables the detection of biological targets, because such targets increase the volume of the beads. Experiments were carried out with a 6. μm wide microwire, which attracted the magnetic beads from a distance of 60. μm, when a current of 30. mA was applied. A sensing space of 30. μm in length and 6. μm in width was defined by the magnetic sensor. The results showed that individual E. coli bacterium inside the sensing space could be detected using super-paramagnetic beads that are 2.8. μm in diameter. The electromagnetic trap setup greatly simplifies the device and reduces the detection process to two steps: (i) mixing the bacteria with magnetic beads and (ii) applying the sample solution to the sensor for measurement, which can be accomplished within about 30. min with a sample volume in the μl range. This setup also ensures that the biosensor can be cleaned easily and re-used immediately. The presented setup is readily integrated on chips via standard microfabrication techniques. © 2014 Elsevier B.V.
dc.publisherElsevier BV
dc.subjectE. coli detection
dc.subjectElectromagnetic trap
dc.subjectMagnetic beads
dc.subjectMagnetic biosensor
dc.subjectMagneto-resistive sensor
dc.titleAn efficient biosensor made of an electromagnetic trap and a magneto-resistive sensor
dc.typeArticle
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
dc.contributor.departmentElectrical Engineering Program
dc.contributor.departmentSensing, Magnetism and Microsystems Lab
dc.identifier.journalBiosensors and Bioelectronics
kaust.personKosel, Jürgen
kaust.personLi, Fuquan


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