title: Surface modification of poly(dimethylsiloxane) microfluidic devices and its application in simultaneous analysis of uric acid and ascorbic acid in human urine.
abstract: A novel and simple method based on layer-by-layer (LBL) technique has been developed for the modification of the channel in PDMS electrophoresis microchip to create a hydrophilic surface with a stable EOF. The functional surface was obtained by sequentially immobilizing chitosan and deoxyribonucleic acid (DNA) onto the microfluidic channel surface using the LBL assembly technique. Compared to the native PDMS microchips, the contact angle of the chitosan-DNA modified PDMS microchips decreased and the EOF increased. Experimental conditions were optimized in detail. The chitosan-DNA modified PDMS microchips exhibited good reproducibility and long-term stability. Separation of uric acid (UA) and ascorbic acid (AA) performed on the modified PDMS microchip generated 43,450 and 46,790 N/m theoretical plates compared with 4048 and 19,847 N/m with the native PDMS microchip. In addition, this method has been successfully applied to real human urine samples, without SPE, with recoveries of 97-105% for UA and AA.
authors.affiliation: Department of Chemistry and Institute for Advanced Study, Nanchang University, Nanchang, PR China.
authors.forename: Ru-Ping
authors.initials: RP
authors.lastname: Liang
authors.forename: Gui-Hua
authors.initials: GH
authors.lastname: Gan
authors.forename: Jian-Ding
authors.initials: JD
authors.lastname: Qiu
mesh_terms: D001205:Ascorbic Acid / Q000652:urine*; D048271:Chitosan / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004563:Electrochemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties; D013997:Time Factors; D014527:Uric Acid / Q000652:urine*
chemical_list: D004129:Dimethylpolysiloxanes; D014527:Uric Acid; C013830:baysilon; D004247:DNA; D048271:Chitosan; D001205:Ascorbic Acid