Steady surface modification of polydimethylsiloxane microchannel and its application in simultaneous analysis of homocysteine and glutathione in human serum.
A novel polydimethylsiloxane (PDMS) surface modification method for microchip electrophoresis has been developed to make a stable and sufficient electroosmotic flow (EOF). Poly(l-glutamic acid) (PGA) which had ionizable carboxyl groups at a high pH-range was immobilized on the surface of microchannel fabricated with PDMS. The surface modification involved surface oxidation by plasma, the silanization of 3-aminopropyldimethylethoxysilane (APDMES) and immobilization of PGA via amide bond. The modified channel was extremely stable against consecutive electric power supply over 5h, and its long-term stability was demonstrated by the efficient separation of four amino acid derivatives reproducibly after a week. Additionally, homocysteine (Hcy), important risk factor of cardiovascular disease, osteoporosis and problems in pregnancy, was successfully measured in human serum in modified PDMS channel with the other thio amino acid simultaneously.
Miyaki
Kyo
K
Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, 1-1, Minamiohsawa, Hachioji, Tokyo 192-0397, Japan.
Zeng
Hu-Lie
HL
Nakagama
Tatsuro
T
Uchiyama
Katsumi
K
D004129:Dimethylpolysiloxanes / Q000737:chemistry; D053841:Electroosmosis; D046209:Electrophoresis, Microchip / Q000295:instrumentation / Q000379:methods*; D005978:Glutathione / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011099:Polyglutamic Acid / Q000737:chemistry; D015203:Reproducibility of Results; D012828:Silicones / Q000737:chemistry; D013499:Surface Properties
D004129:Dimethylpolysiloxanes; D012828:Silicones; D006710:Homocysteine; D011099:Polyglutamic Acid; C013830:baysilon; D005978:Glutathione