On-chip immunoassay using electrostatic assembly of streptavidin-coated bead micropatterns.
We propose an original concept for a sandwich immunoassay that is completely performed on-chip using streptavidin-coated beads as substrate. The latter are electrostatically self-assembled on aminosilane micropatterns at the bottom of a microfluidic channel. We use mouse IgG diluted in phosphate buffered saline (PBS) with 1% bovine serum albumin (BSA) solution as target antigen. The fluorescent sandwich immunocomplex is formed on the beads during the operation of the chip both in stop-flow and continuous-flow modes. Target mouse IgG antigen is detected down to a concentration of 15 ng/mL in stop-flow mode and 250 pg/mL in continuous-flow mode, using only 1300 nL of sample volume. We also demonstrate the possibility of simultaneous detection of two different antigens in a PBS-BSA solution using a dual microfluidic channel structure.
Sivagnanam
Venkataragavalu
V
Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland. venkataragavalu.sivagnanam@epfl.ch
Song
Bo
B
Vandevyver
Caroline
C
Gijs
Martin A M
MA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015374:Biosensing Techniques; D002417:Cattle; D007118:Immunoassay; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D051379:Mice; D046210:Microfluidic Analytical Techniques; D020411:Oligonucleotide Array Sequence Analysis; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D055672:Static Electricity; D019809:Streptavidin / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D012710:Serum Albumin, Bovine; D019809:Streptavidin