title: A single-walled carbon nanotube thin film-based pH-sensing microfluidic chip.
abstract: A novel microfluidic pH-sensing chip was developed based on pH-sensitive single-walled carbon nanotubes (SWCNTs). In this study, the SWCNT thin film acted both as an electrode and a pH-sensitive membrane. The potentiometric pH response was observed by electronic structure changes in the semiconducting SWCNTs in response to the pH level. In a microfluidic chip consisting of a SWCNT pH-sensing working electrode and an Ag/AgCl reference electrode, the calibration plot exhibited promising pH-sensing performance with an ideal Nernstian response of 59.71 mV pH(-1) between pH 3 and 11 (standard deviation of the sensitivity is 1.5 mV pH(-1), R(2) = 0.985). Moreover, the SWCNT electrode in the microfluidic device showed no significant variation at any pH value in the range of the flow rate between 0.1 and 15 μl min(-1). The selectivity coefficients of the SWCNT electrode revealed good selectivity against common interfering ions.
authors.affiliation: Department of Bionano Engineering, Hanyang University, Ansan 425-791, South Korea. ghseong@hanyang.ac.kr.
authors.forename: Cheng Ai
authors.initials: CA
authors.lastname: Li
authors.forename: Kwi Nam
authors.initials: KN
authors.lastname: Han
authors.forename: Xuan-Hung
authors.initials: XH
authors.lastname: Pham
authors.forename: Gi Hun
authors.initials: GH
authors.lastname: Seong
mesh_terms: D006863:Hydrogen-Ion Concentration; D044085:Microfluidics / Q000295:instrumentation*; D037742:Nanotubes, Carbon
chemical_list: D037742:Nanotubes, Carbon