| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 599819 | Colloids and Surfaces B: Biointerfaces | 2013 | 8 Pages |
•Spatially defined hydrophobic coating was achieved on microwell-patterned substrate.•Submicron-scale microwells were fabricated using UV curable polymer.•PDMS contact onto a partially cured polymer and UV curing induced silicone transfer.•A surface with dual wettabilities (hydrophilic/hydrophobic) was obtained.•Targeted immobilization of functionalized beads into microwells was demonstrated.
In this study, a simple and facile scheme for selectively hydrophobizing microwell-patterned hydrophilic polymer substrate is demonstrated, and applied for a targeted adhesion. Microwell-patterned polymer substrate was replicated from a silicon mold using a photocurable prepolymer under ultraviolet (UV) light for 30 min. While the surface of the replica was partially cured, it was contact printed with a flat, hydrophobic poly(dimethylsiloxane) (PDMS) elastomer, and the assembly was further cured under UV light for approximately 3 h and detached. In this manner, the PDMS molecules were transferred selectively onto the protruding regions of the partially cured microwell-patterned substrate, while the inner walls of the microwells remained hydrophilic. The surface hydrophobization was characterized by contact angle measurement and X-ray photoelectron spectroscopy (XPS). In addition, time-dependent contact angle variations were investigated to verify the robustness and durability of the coating of the PDMS functional group. As a proof-of-concept experiment, functionalized polymer beads were targeted and successfully guided selectively into arrays of microwells without being adsorbed onto the protruding regions of the microwell-patterned substrate, which could further be applied for the targeted immobilization of biomolecules with high selectivity in a relatively simple and facile manner.
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