title: Amperometric immunosensor for rapid detection of Mycobacterium tuberculosis.
abstract: Tuberculosis(TB) has been a major public health problem, which can be better controlled by using accurate and rapid diagnosis in low-resource settings. A simple, portable, and sensitive detection method is required for point-of-care (POC) settings. This paper studies an amperometric biosensor using a microtip immunoassay for a rapid and low cost detection ofMycobacterium Tuberculosis(MTB) in sputum. MTB in sputum is specifically captured on the functionalized microtip surface and detected by electric current. According to the numerical study, the current signal on microtip surface is linearly changed with increasing immersion depth. Using a reference microtip, the immersion depth is compensated for a sensing microtip. On the microtip surface, target bacteria are concentrated and organized by a coffee ring effect, which amplifies the electric current. To enhance the signal-to-noise ratio, both the sample processing- and rinsing steps are presented with use of deionized water as a medium for the amperometric measurement. When applied to cultured MTB cells spiked into human sputum, the detection limit was 100 CFU/mL, comparable to a more labor-intensive fluorescence detection method reported previously.
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, WA 98195.
authors.forename: Morgan
authors.initials: M
authors.lastname: Hiraiwa
authors.affiliation: School of Engineering and Computer Science, Washington State University, Vancouver, WA, 98686.
authors.forename: Jong-Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, WA 98195.
authors.forename: Hyun-Boo
authors.initials: HB
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, WA 98195.
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Inoue
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195.
authors.forename: Annie L
authors.initials: AL
authors.lastname: Becker
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195.
authors.forename: Kris M
authors.initials: KM
authors.lastname: Weigel
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195.
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Cangelosi
authors.affiliation: NanoFacture, Inc., 2601 151 Pl NE, Redmond, WA 98052.
authors.forename: Kyong-Hoon
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, WA 98195.
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Chung