title: Fabrication of microfluidic devices containing patterned microwell arrays.
abstract: A rapid fabrication and prototyping technique to incorporate microwell arrays with sub-10 μm features within a single layer of microfluidic circuitry is presented. Typically, the construction of devices that incorporate very small architecture within larger components has required the assembly of multiple elements to form a working device. Rapid, facile production of a working device using only a single layer of molded polydimethylsiloxane (PDMS) and a glass support substrate is achieved with the reported fabrication technique. A combination of conventional wet-chemical etching for larger (≥20 μm) microchannel features and focused ion beam (FIB) milling for smaller (≤10 μm) microwell features was used to fabricate a monolithic glass master mold. PDMS/glass hybrid chips were then produced using simple molding and oxygen plasma bonding methods. Microwell structures were loaded with 3 μm antibody-functionalized dye-encoded polystyrene spheres, and a sandwich immunoassay for common cytokines was performed to demonstrate proof-of-principle. Potential applications for this device include highly parallel multiplexed sandwich immunoassays, DNA/RNA hybridization analyses, and enzyme linked immunosorbent assay (ELISA). The fabrication technique described can be used for rapid prototyping of devices wherever submicrometer- to micrometer-sized features are incorporated into a microfluidic device.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapman Hall CB#3216, Chapel Hill, North Carolina 27599, USA.
authors.forename: W Hampton
authors.initials: WH
authors.lastname: Henley
authors.forename: Patty J
authors.initials: PJ
authors.lastname: Dennis
authors.forename: J Michael
authors.initials: JM
authors.lastname: Ramsey
mesh_terms: D055910:Antibodies, Immobilized / Q000276:immunology; D004396:Coloring Agents / Q000737:chemistry; D016207:Cytokines / Q000032:analysis / Q000276:immunology; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D005898:Glass; D007118:Immunoassay; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D011137:Polystyrenes / Q000737:chemistry
chemical_list: D055910:Antibodies, Immobilized; D004396:Coloring Agents; D016207:Cytokines; D004129:Dimethylpolysiloxanes; D011137:Polystyrenes; C013830:baysilon