title: In-situ grafting hydrophilic polymer on chitosan modified poly(dimethylsiloxane) microchip for separation of biomolecules.
abstract: In this paper, a simple and green modification method is developed for biomolecules analysis on poly(dimethylsiloxane) (PDMS) microchip with successful depression of nonspecific biomolecules adsorption. O-[(N-succinimdyl)succiny]-o'-methyl-poly(ethylene glycol) was explored to form hydrophilic surface via in-situ grafting onto pre-coated chitosan (Chit) from aqueous solution in the PDMS microchannel. The polysaccharide chains backbone of Chit was strongly attracted onto the surface of PDMS via hydrophobic interaction combined with hydrogen bonding in an alkaline medium. The methyl-poly(ethylene glycol) (mPEG) could produce hydrophilic domains on the mPEG/aqueous interface, which generated brush-like coating in this way and revealed perfect resistance to nonspecific adsorption of biomolecules. This strategy could greatly improve separation efficiency and reproducibility of biomolecules. Amino acids and proteins could be efficiently separated and successfully detected on the coated microchip coupled with end-channel amperometric detection at a copper electrode. In addition, it offered an effective means for preparing biocompatible and hydrophilic surface on microfluidic devices, which may have potential use in the biological analysis.
authors.affiliation: Key Lab of Analytical Chemistry for Life Science (MOE), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Ai-Jun
authors.initials: AJ
authors.lastname: Wang
authors.forename: Jing-Juan
authors.initials: JJ
authors.lastname: Xu
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification*; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004586:Electrophoresis / Q000379:methods; D057927:Hydrophobic and Hydrophilic Interactions; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D013499:Surface Properties
chemical_list: D000596:Amino Acids; D020099:Coated Materials, Biocompatible; D004129:Dimethylpolysiloxanes; D011108:Polymers; D011506:Proteins; D048271:Chitosan