title: ZnO-Based Microfluidic pH Sensor: A Versatile Approach for Quick Recognition of Circulating Tumor Cells in Blood.
abstract: The present study is concerned about the development of highly sensitive and stable microfluidic pH sensor for possible identification of circulating tumor cells (CTCs) in blood. The precise pH measurements between silver-silver chloride (Ag/AgCl) reference electrode and zinc oxide (ZnO) working electrode have been investigated in the microfluidic device. Since there is a direct link between pH and cancer cells, the developed device is one of the valuable tools to examine circulating tumor cells (CTCs) in blood. The ZnO-based working electrode was deposited by radio frequency (rf) sputtering technique. The potential voltage difference between the working and reference electrodes (Ag/AgCl) is evaluated on the microfluidic device. The ideal Nernstian response of -43.71165 mV/pH was achieved along with high stability and quick response time. Finally, to evaluate the real time capability of the developed microfluidic device, in vitro testing was done with A549, A7r5, and MDCK cells.
authors.affiliation: Micro/Nano Technology Center, ‡Graduate School of Science and Technology, §Department of Mechanical Engineering, and ∥Department of Precision Engineering, Tokai University , 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Ganesh Kumar
authors.identifier: http://orcid.org/0000-0003-0046-4676
authors.initials: GK
authors.lastname: Mani
authors.affiliation: Micro/Nano Technology Center, ‡Graduate School of Science and Technology, §Department of Mechanical Engineering, and ∥Department of Precision Engineering, Tokai University , 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Morohoshi
authors.affiliation: Micro/Nano Technology Center, ‡Graduate School of Science and Technology, §Department of Mechanical Engineering, and ∥Department of Precision Engineering, Tokai University , 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yasoda
authors.affiliation: Micro/Nano Technology Center, ‡Graduate School of Science and Technology, §Department of Mechanical Engineering, and ∥Department of Precision Engineering, Tokai University , 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Yokoyama
authors.affiliation: Micro/Nano Technology Center, ‡Graduate School of Science and Technology, §Department of Mechanical Engineering, and ∥Department of Precision Engineering, Tokai University , 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kimura
authors.affiliation: Micro/Nano Technology Center, ‡Graduate School of Science and Technology, §Department of Mechanical Engineering, and ∥Department of Precision Engineering, Tokai University , 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Tsuchiya
mesh_terms: D004566:Electrodes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D044085:Microfluidics; D009360:Neoplastic Cells, Circulating; D015034:Zinc Oxide
chemical_list: D015034:Zinc Oxide
keywords: ZnO; circulating tumor cells; in vitro testing; pH sensor; sputtering; thin films