title: Preconcentration of diluted mixed-species samples following separation and collection in a micro-nanofluidic device.
abstract: A microfluidic device consisting of a nanoscale Nafion membrane and a polydimethylsiloxane microchannel is proposed for the preconcentration of diluted multi-mixed species samples then following separation and collection. When an electric field is applied across the microchip, an accumulation of the mixed-species sample occurs at the junction between the microchannel and the membrane by means of ion concentration polarization effect. A separation of the sample then takes place due to the difference in the electrophoretic mobilities of the sample components. Finally, the component of interest is guided to a collection reservoir by manipulating the external potential configuration and is trapped in place by means of a magnetically actuated valve. The preconcentration performance of the proposed device is evaluated in both straight and convergent microchannels using a fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) sample. It is shown that a preconcentration factor of 40 times can be achieved using a straight microchannel. By contrast, the preconcentration factor increases to 50 times when using a convergent channel. The practical feasibility of the proposed device is demonstrated by performing the preconcentration, separation, and collection of a mixed FITC-BSA and Tetramethylrhodamine sample.
authors.affiliation: Department of Engineering Science, National Cheng Kung University , Tainan, Taiwan.
authors.forename: Yi-Ying
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Department of Engineering Science, National Cheng Kung University , Tainan, Taiwan.
authors.forename: Ping-Hsien
authors.initials: PH
authors.lastname: Chiu
authors.affiliation: Medical Device Innovation Center, National Cheng Kung University , Tainan, Taiwan.
authors.forename: Chen-Hsun
authors.initials: CH
authors.lastname: Weng
authors.affiliation: Department of Engineering Science, National Cheng Kung University , Tainan, Taiwan.
authors.forename: Ruey-Jen
authors.identifier: 0000-0002-1958-0389
authors.initials: RJ
authors.lastname: Yang