title: High-performance immunoassays based on through-stencil patterned antibodies and capillary systems.
abstract: We present a simple method to pattern capture antibodies (cAbs) on poly(dimethylsiloxane) (PDMS), with high accuracy and in a manner compatible with mass fabrication for use with capillary systems (CSs), using stencils microfabricated in Si. Capture antibodies are patterned as 60-270 microm wide and 2 mm long lines on PDMS and used with CSs that have been optimized for convenient handling, pipetting of solutions, pumping of liquids, such as human blood serum, and visualization of signals for fluorescence immunoassays. With the use of this method, C-reactive protein (CRP) is detected with a sensitivity of 0.9 ng mL(-1) (7.8 pM) in 1 microL of CRP-spiked human serum, within 11 min and using only four pipetting steps and a total volume of sample and reagents of 1.35 microL. This exemplifies the high performances that can be achieved using this approach and an otherwise conventional surface sandwich fluorescence immunoassay. This method is simple and flexible and should therefore be applicable to a large number of demanding immunoassays.
authors.affiliation: University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland, and IBM Research GmbH, Zurich Research Laboratory, Säumerstrasse 4, 8803 Rüschlikon, Switzerland.
authors.forename: Jörg
authors.initials: J
authors.lastname: Ziegler
authors.forename: Martin
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Patrick
authors.initials: P
authors.lastname: Hunziker
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Delamarche
mesh_terms: D000906:Antibodies / Q000737:chemistry*; D002097:C-Reactive Protein / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D044085:Microfluidics; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D000906:Antibodies; D004129:Dimethylpolysiloxanes; D012828:Silicones; D012710:Serum Albumin, Bovine; D012965:Sodium Chloride; C013830:baysilon; D002097:C-Reactive Protein