title: A two-stage microresistive pulse immunosensor for pathogen detection.
abstract: We present a two-stage immunosensor for pathogen detection in a mixed population. In this approach, antibody-conjugated microparticles were used to functionalize the surface of the capture chamber via a convenient magnetic method and a two-stage resistive pulse sensor was used to detect and quantify pathogen cells. We firstly tested the capture efficiency of the functionalized capture chamber. The specific capture efficiency of S. cerevisiae is greater than 94.8%, while the non-specific capture efficiency is 3.4%. We showed that the device can accurately measure pure S. cerevisiae at concentrations ranging from 1.0 to 8.0 × 10(3) cells per μL. We performed S. cerevisiae measurements in a mixture with Chlorella. Both cells have similar sizes. For S. cerevisiae to Chlorella ratios ranging from 1.0 to 2.0, the measurement error was less than 7%, while the error became 20% to 32% for lower ratios ranging from 0.1 to 0.5 caused by nonspecific attachment. We demonstrated that this device is able to isolate target cells and quantitatively measure the cell population in a short time. This device can be potentially used for pathogen detection in the food industry, biological research and clinical applications.
authors.affiliation: Department of Mechanical Engineering, University of Akron, OH, USA. jzhe@uakron.edu.
authors.forename: Yu
authors.initials: Y
authors.lastname: Han
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wu
authors.forename: Gang
authors.initials: G
authors.lastname: Cheng
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhe
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002708:Chlorella / Q000302:isolation & purification; D017097:Electric Impedance; D004867:Equipment Design; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D057230:Limit of Detection; D055616:Microtechnology / Q000295:instrumentation / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification*