title: A dynamically modified microfluidic poly(dimethylsiloxane) chip with electrochemical detection for biological analysis.
abstract: Separation and direct detection of amino acids, glucose and peptide in a 3.1 cm separation channel made of poly(dimethylsiloxane) (PDMS) with end-column amperometric detection at a copper microdisk electrode was developed. This system is the integration of a normal sized working electrode with electrochemical detection on a PDMS microfabricated device. The PDMS channels dynamically modified by 2-morpholinoethanesulfonic acid (MES) show less adsorption and more enhanced efficiency than that of unmodified ones when applied to separations of these biological molecules. The migration time is less than 100 s and the reproducibility of migration time is satisfactory with relative standard deviation (RSD) of 2.8% in 19 successive injections. The limits of detection of arginine (Arg), glucose, and methionine-glycine (Met-Gly) are estimated to be 2.0, 8.5, and 64.0 microM at S/N = 3, approximately 0.5-16.0 fmol, respectively. Variances influencing the separation efficiency and amperometric response, including injection, separation voltage, detection potential, or concentration of buffer and additive, are assessed and optimized.
authors.affiliation: Institute of Analytical Science, The State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Dou
authors.forename: Ning
authors.initials: N
authors.lastname: Bao
authors.forename: Jing-Juan
authors.initials: JJ
authors.lastname: Xu
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Chen
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry; D000596:Amino Acids / Q000302:isolation & purification*; D001120:Arginine / Q000302:isolation & purification; D004129:Dimethylpolysiloxanes; D004151:Dipeptides / Q000302:isolation & purification; D004563:Electrochemistry; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D005947:Glucose / Q000302:isolation & purification; D008832:Microchemistry; D008904:Miniaturization; D009025:Morpholines / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents
chemical_list: D017738:Alkanesulfonic Acids; D000596:Amino Acids; D004129:Dimethylpolysiloxanes; D004151:Dipeptides; D009025:Morpholines; D013501:Surface-Active Agents; C098230:methionylglycine; C004550:2-(N-morpholino)ethanesulfonic acid; D001120:Arginine; D005947:Glucose