title: High-speed, whole-column fluorescence imaging detection for isoelectric focusing on a microchip using an organic light emitting diode as light source.
abstract: An integrated and simplified microfluidic device using a 250 microm x 1-4 cm of organic light emitting diode (OLED) array as a two-dimensional light source for single-channel and multichannel whole-column imaging detection was developed. This fluorescence detection system was used for isoelectric focusing (IEF) of R-phycoerythrin in a microchip. The IEF conditions were optimized, and the total analysis time was extremely reduced to 30 s for 2-cm-long microchannels at 700 V/cm of electric field strength without the presence of electroosmotic flow. The compression of pH gradient caused by electrolytes drawing into the microchannels was efficiently restrained when 1% hydroxylpropylmethyl cellulose in 2% ampholyte was used as the carrier for IEF. Under optimized IEF conditions, the detection limit of this system was approximately 0.6 microg/mL or 45 pg at 75 nL/column injection of R-phycoerythrin. This OLED-induced fluorescence detection system for WCID provides a high-speed IEF technique with quantitative ability and the potential for high integration and throughput microchip systems.
authors.affiliation: Department of Chemistry, Tsinghua University, Beijing 100084, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yao
authors.forename: Huihua
authors.initials: H
authors.lastname: Yang
authors.forename: Qionglin
authors.initials: Q
authors.lastname: Liang
authors.forename: Guoan
authors.initials: G
authors.lastname: Luo
authors.forename: Liduo
authors.initials: L
authors.lastname: Wang
authors.forename: Kangning
authors.initials: K
authors.lastname: Ren
authors.forename: Yudi
authors.initials: Y
authors.lastname: Gao
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D005453:Fluorescence; D007525:Isoelectric Focusing / Q000379:methods*; D008027:Light; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D010799:Phycoerythrin / Q000032:analysis
chemical_list: D010799:Phycoerythrin