ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Analysis of Reaction-Transport Phenomena in a Microfluidic System for the Detection of IgG
M. Přibyl, V. Knápková, D. Šnita, and M. Marek
Department of Chemical Engineering and Center for Nonlinear Dynamics of Chemical and Biological Systems,
Institute of Chemical Technology, CZ-166 28 Prague
Abstract: A spatially two-dimensional mathematical model of microfluidic biosensor for immunological determination
of human immunoglobulin G (IgG) with the use of Protein A (PA) immobilized on the
internal walls of a microchannel is presented. Convection flow in the microdevice is induced by an
imposed difference of electric potential (electroosmosis). In the model, the electroosmotic convection
is described using the slip boundary conditions that can be defined by the Helmholtz—Smoluchowski
Incubation phase (formation of the immobile PA—IgG complex) of the immunoassay has been
studied. Effects of the antibody concentration in a sample, the imposed difference of electric potential,
the surface heterogeneities in the reaction zone, and other model parameters on the saturation
time were determined.
It was found that the surface heterogeneities could form complex velocity fields at the location
of the adsorption zone: either an intensive flow at the microchannel walls or the nozzle-like flow.
Generally, the local acceleration of the flow causes the decrease of the mass-transfer resistance.
Further, imposed electric field of a proper orientation was able to shorten the incubation phase
to 600 s, assuming the microchannel device with the diameter of 100 µm and the chosen reaction
kinetics. Hence, the incubation phase could be substantially reduced enabling, e.g., fast diagnostics.
Simulation of the effects of the antibody sample concentration revealed good qualitative agreement
with experimental data obtained in a similar microfluidic device (published by Dodge et al., Anal.
Chem. 73, 3400 (2001)).
Full paper in Portable Document Format: 596aa434.pdf
Chemical Papers 59 (6a) 434–440 (2005)
Sunday, November 28, 2021