title: Wheatstone bridge giant-magnetoresistance based cell counter.
abstract: A Wheatstone bridge giant magnetoresistance (GMR) biosensor was proposed here for the detection and counting of magnetic cells. The biosensor was made of a top-pinned spin-valve layer structure, and it was integrated with a microchannel possessing the function of hydrodynamic focusing that allowed the cells to flow in series one by one and ensured the accuracy of detection. Through measuring the magnetoresistance variation caused by the stray field of the magnetic cells that flowed through the microchannel above the GMR biosensor, we can not only detect and count the cells but we can also recognize cells with different magnetic moments. In addition, a magnetic field gradient was applied for the separation of different cells into different channels.
authors.affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, Taiwan ROC.
authors.forename: Chiun-Peng
authors.initials: CP
authors.lastname: Lee
authors.affiliation: Institute of Nanoengineering and Microsystems, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan ROC.
authors.forename: Mei-Feng
authors.initials: MF
authors.lastname: Lai
authors.affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, Taiwan ROC.
authors.forename: Hao-Ting
authors.initials: HT
authors.lastname: Huang
authors.affiliation: Institute of Nanoengineering and Microsystems, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan ROC.
authors.forename: Chi-Wen
authors.initials: CW
authors.lastname: Lin
authors.affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, Taiwan ROC. Electronic address: wei@pme.nthu.edu.tw.
authors.forename: Zung-Hang
authors.initials: ZH
authors.lastname: Wei
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation; D002452:Cell Count / Q000295:instrumentation*; D002460:Cell Line; D045744:Cell Line, Tumor; D002469:Cell Separation / Q000295:instrumentation; D004867:Equipment Design; D006801:Humans; D057446:Hydrodynamics; D008280:Magnetics / Q000295:instrumentation*; D051379:Mice
keywords: Biosensor; Cell counting; Cell separation; Giant magnetoresistance