caa a22 4500 605480427 CHVBK 20210128100415.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s10544-015-9940-2 doi (NATIONALLICENCE)springer-10.1007/s10544-015-9940-2 Preconcentration of diluted biochemical samples using microchannel with integrated nanoscale Nafion membrane [Elektronische Daten] [Chen-Chiao Chao, Ping-Hsien Chiu, Ruey-Jen Yang] A microfluidic preconcentration device comprising a microchannel and a surface-patterned nanoscale Nafion membrane is proposed. Given the application of an electric field across the chip, the nanopore within Nafion membrane becomes ion selective due to an overlapping of the electric double layer. The resulting difference in flux of the co- and counter-ions within the membrane nanopore prompts the formation of a concentration gradient and leads to a gradual accumulation of the co-ions at the micro-nano junction. It is shown experimentally that the rate of concentration and the preconcentration factor both increase with an increasing electrical field intensity. The preconcentration performance in a straight microchannel is compared with that in a convergent microchannel using fluorescein disodium salt dehydrate and Fluorescein isothiocyanate (FITC)-labeled bovine serum albumin samples. The results show that the reduced cross-sectional area of the convergent microchannel increases the preconcentration factor compared to that obtained in a straight microchannel and yields a significant reduction in the preconcentration time. Springer Science+Business Media New York, 2015 Concentration polarization nationallicence Microfluidics nationallicence Preconcentration nationallicence Nano-junction nationallicence Chao Chen-Chiao Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan aut Chiu Ping-Hsien Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan aut Yang Ruey-Jen Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/2(2015-04-01), 1-9 1387-2176 17:2<1 2015 17 10544 https://doi.org/10.1007/s10544-015-9940-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-015-9940-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chao Chen-Chiao Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan aut NATIONALLICENCE 700 1- Chiu Ping-Hsien Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan aut NATIONALLICENCE 700 1- Yang Ruey-Jen Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/2(2015-04-01), 1-9 1387-2176 17:2<1 2015 17 10544