TY - JOUR
T1 - Flow sandwich-type immunoassay in microfluidic devices based on negative dielectrophoresis
AU - Yasukawa, Tomoyuki
AU - Suzuki, Masato
AU - Sekiya, Takashi
AU - Shiku, Hitoshi
AU - Matsue, Tomokazu
N1 - Funding Information:
This work was partly supported by a Grant-in-Aid for Scientific Research (No. 17750149) from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
PY - 2007/5/15
Y1 - 2007/5/15
N2 - Microparticles have been manipulated in a microfluidic channel by means of negative dielectrophoresis (n-DEP), and the approach applied to a heterogeneous immunoassay system. A microfluidic device, with three-dimensional (3-D) microelectrodes fabricated on two substrates, was used to manipulate particle flow in the channel and to capture the particles in the caged area that was enclosed by the collector electrodes. Polystyrene microparticles (6 μm diameters) modified with anti-mouse immunoglobulin G (IgG) were manipulated and captured in the caged area when surrounded by intense n-DEP electric fields. Specifically, particles were trapped when AC voltages with amplitudes of 6-15 Vpeak and frequencies over 500 kHz were applied to the two facing microelectrodes. A heterogeneous sandwich immunoassay was achieved by successively injecting a sample solution containing mouse antigen (IgG), and a solution containing a secondary antibody with a signal source (FITC-labeled anti-mouse IgG antibody), into the channel. The fluorescence intensity from captured particles in the caged area increased with increasing concentrations (10 ng/ml to 10 μg/ml) of mouse IgG. The described system enables mouse IgG to be assayed in 40 min. Thus, the automatic separation of free fractions from desired analytes and labeled antibodies can be achieved using a microfluidic device based on n-DEP.
AB - Microparticles have been manipulated in a microfluidic channel by means of negative dielectrophoresis (n-DEP), and the approach applied to a heterogeneous immunoassay system. A microfluidic device, with three-dimensional (3-D) microelectrodes fabricated on two substrates, was used to manipulate particle flow in the channel and to capture the particles in the caged area that was enclosed by the collector electrodes. Polystyrene microparticles (6 μm diameters) modified with anti-mouse immunoglobulin G (IgG) were manipulated and captured in the caged area when surrounded by intense n-DEP electric fields. Specifically, particles were trapped when AC voltages with amplitudes of 6-15 Vpeak and frequencies over 500 kHz were applied to the two facing microelectrodes. A heterogeneous sandwich immunoassay was achieved by successively injecting a sample solution containing mouse antigen (IgG), and a solution containing a secondary antibody with a signal source (FITC-labeled anti-mouse IgG antibody), into the channel. The fluorescence intensity from captured particles in the caged area increased with increasing concentrations (10 ng/ml to 10 μg/ml) of mouse IgG. The described system enables mouse IgG to be assayed in 40 min. Thus, the automatic separation of free fractions from desired analytes and labeled antibodies can be achieved using a microfluidic device based on n-DEP.
KW - Dielectrophoresis
KW - Microfluidic device
KW - Microparticles
KW - Sandwich immunoassay
KW - Separation
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U2 - 10.1016/j.bios.2006.11.010
DO - 10.1016/j.bios.2006.11.010
M3 - Article
C2 - 17187978
AN - SCOPUS:33947579961
VL - 22
SP - 2730
EP - 2736
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
SN - 0956-5663
IS - 11
ER -