Microfluidic immunoassay for bacterial toxins with supported phospholipid bilayer membranes on poly(dimethylsiloxane)

被引:111
作者
Phillips, KS [1 ]
Cheng, Q [1 ]
机构
[1] Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA
关键词
D O I
10.1021/ac049356+
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
We report a heterogeneous immunoassay for cholera toxin (CT) using supported bilayer membranes (SBMs) in a poly(dimethylsiloxane) (PDMS) microfluidic device. Phosphatidylcholine membranes assembled on plasma-oxidized PDMS by vesicle fusion bring about favorable surface properties, such as improved wettability and protein resistance. Contact angle measurements show that the lipid membranes can preserve hydrophilic surfaces for hours, whereas untreated substrates rapidly undergo hydrophobic recovery. Fluorescence recovery after photobleaching performed in situ reveals that the membranes have relatively high lateral mobility. Experimental data-fitting to theoretical models yields diffusion coefficients of 1.8 +/- 0.7 mum(2)/s on PDMS and 3.4 +/- 0.8 mum(2)/s on glass. Fluorescence studies utilizing tagged proteins show that SBMs reduce nonspecific adsorption of avidin and BSA on PDMS by 2-3 orders of magnitude, as compared to that on plasma oxidized surfaces. SBMs and their protein-resistant properties are not significantly affected by long flow times, indicating good membrane stability. These studies increase our understanding of the relationship between molecular level interactions and membrane properties, allowing for development of a rapid heterogeneous immunoassay for CT in PDMS microchips with cell surface receptor molecules. Using optimized sample injection and buffer washing conditions, microfluidic immunoassay of CT is complete within 25 min, and a dynamic range over 3 orders of magnitude with a detection limit of 8 fmol of toxin is achieved.
引用
收藏
页码:327 / 334
页数:8
相关论文
共 47 条
[1]   SIMPLE METHOD FOR PREPARATION OF HOMOGENEOUS PHOSPHOLIPID VESICLES [J].
BARENHOLZ, Y ;
GIBBES, D ;
LITMAN, BJ ;
GOLL, J ;
THOMPSON, TE ;
CARLSON, FD .
BIOCHEMISTRY, 1977, 16 (12) :2806-2810
[2]   Two-step formation of streptavidin-supported lipid bilayers by PEG-triggered vesicle fusion. Fluorescence and atomic force microscopy characterization [J].
Berquand, A ;
Mazeran, PE ;
Pantigny, J ;
Proux-Delrouyre, V ;
Laval, JM ;
Bourdillon, C .
LANGMUIR, 2003, 19 (05) :1700-1707
[3]   ALLOGENEIC STIMULATION OF CYTO-TOXIC T-CELLS BY SUPPORTED PLANAR MEMBRANES [J].
BRIAN, AA ;
MCCONNELL, HM .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1984, 81 (19) :6159-6163
[4]   Segregation of micrometer-dimension biosensor elements on a variety of substrate surfaces [J].
Brooks, SA ;
Dontha, N ;
Davis, CB ;
Stuart, JK ;
O'Neill, G ;
Kuhr, WG .
ANALYTICAL CHEMISTRY, 2000, 72 (14) :3253-3259
[5]   A microchip-based multianalyte assay system for the assessment of cardiac risk [J].
Christodoulides, N ;
Tran, M ;
Floriano, PN ;
Rodriguez, M ;
Goodey, A ;
Ali, M ;
Neikirk, D ;
McDevitt, JT .
ANALYTICAL CHEMISTRY, 2002, 74 (13) :3030-3036
[6]   Phospholipid bilayer coatings for the separation of proteins in capillary electrophoresis [J].
Cunliffe, JM ;
Baryla, NE ;
Lucy, CA .
ANALYTICAL CHEMISTRY, 2002, 74 (04) :776-783
[7]   Electrokinetically driven microfluidic chips with surface-modified chambers for heterogeneous immunoassays [J].
Dodge, A ;
Fluri, K ;
Verpoorte, E ;
de Rooij, NF .
ANALYTICAL CHEMISTRY, 2001, 73 (14) :3400-3409
[8]   Rapid prototyping of microfluidic systems in poly(dimethylsiloxane) [J].
Duffy, DC ;
McDonald, JC ;
Schueller, OJA ;
Whitesides, GM .
ANALYTICAL CHEMISTRY, 1998, 70 (23) :4974-4984
[9]   Development and characterization of an ELISA assay in PDMS microfluidic channels [J].
Eteshola, E ;
Leckband, D .
SENSORS AND ACTUATORS B-CHEMICAL, 2001, 72 (02) :129-133
[10]   Detection of biological toxins on an active electronic microchip [J].
Ewalt, KL ;
Haigis, RW ;
Rooney, R ;
Ackley, D ;
Krihak, M .
ANALYTICAL BIOCHEMISTRY, 2001, 289 (02) :162-172