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A Sol–Gel‐Modified Poly(methyl methacrylate) Electrophoresis Microchip with a Hydrophilic Channel Wall
Author(s) -
Chen Gang,
Xu Xuejiao,
Lin Yuehe,
Wang Joseph
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200700242
Subject(s) - methyl methacrylate , materials science , electrophoresis , poly(methyl methacrylate) , chromatography , microfluidics , methacrylate , capillary electrophoresis , analytical chemistry (journal) , polymer , chemistry , composite material , polymerization , nanotechnology
A sol–gel method was employed to fabricate a poly(methyl methacrylate) (PMMA) electrophoresis microchip that contains a hydrophilic channel wall. To fabricate such a device, tetraethoxysilane (TEOS) was injected into the PMMA channel and was allowed to diffuse into the surface layer for 24 h. After removing the excess TEOS, the channel was filled with an acidic solution for 3 h. Subsequently, the channel was flushed with water and was pretreated in an oven to obtain a sol–gel‐modified PMMA microchip. The water contact angle for the sol–gel‐modified PMMA was ≈27.4° compared with ≈66.3° for the pure PMMA. In addition, the electro‐osmotic flow increased from 2.13×10 −4 cm 2 V −1 s −1 for the native‐PMMA channel to 4.86×10 −4 cm 2 V −1 s −1 for the modified one. The analytical performance of the sol–gel‐modified PMMA microchip was demonstrated for the electrophoretic separation of several purines, coupled with amperometric detection. The separation efficiency of uric acid increased to 74 882.3 m −1 compared with 14 730.5 m −1 for native‐PMMA microchips. The result of this simple modification is a significant improvement in the performance of PMMA for microchip electrophoresis and microfluidic applications.