title: Environmentally friendly surface modification of PDMS using PEG polymer brush.
abstract: A PEG-NH2-based environmentally friendly surface modification strategy was developed for PDMS microchips to prevent protein adsorption and to enhance separation performance. PEG-NH2 was synthesized using a modified synthesis procedure. A two-step grafting method was used for PDMS modification. FTIR absorption by attenuated total reflection and contact angle measurements verified the successful grafting of PEG-NH2 onto the PDMS surface. Subsequent EOF Measurements and protein adsorption studies of PEG-modified PDMS microchips revealed noticeable EOF suppression and resistance to nonspecific protein adsorption for more than 30 days. Separation of four FITC-labeled amino acids was further demonstrated with high repeatability and reproducibility. Comparison of electrophoresis of 3-(2-furoyl)quinoline-2-carboxaldehyde-labeled BSA using PDMS microchips before and after surface modification resulted in significantly improved electrophoretic performance of the PEG-modified PDMS microchips, suggesting that our PEG grafting method successfully modified PDMS surface property and prevented adsorption of proteins. We expect that this environmentally friendly surface modification method will be useful for future protein separations with long-term surface stability.
authors.affiliation: The Key Laboratory of Biomedical Photonics of MOE-Hubei Bioinformatics and Molecular Imaging Key Laboratory-Division of Biomedical Photonics at Wuhan National Laboratory for Optoelectronics, Department of Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, P. R. China.
authors.forename: Zhaowei
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Feng
authors.forename: Qingming
authors.initials: Q
authors.lastname: Luo
authors.forename: Bi-Feng
authors.initials: BF
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D000596:Amino Acids / Q000302:isolation & purification; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D053841:Electroosmosis; D046209:Electrophoresis, Microchip / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D055772:Green Chemistry Technology / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009757:Nylons / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011506:Proteins / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000596:Amino Acids; D004129:Dimethylpolysiloxanes; D009757:Nylons; D011506:Proteins; C085707:poly(dimethylsiloxane)-polyamide copolymer; D011092:Polyethylene Glycols; D016650:Fluorescein-5-isothiocyanate