The present invention provides crosslinked epoxy-functional copolymer films and microarrays built from the crosslinked epoxy-functional copolymer films. Microarrays incorporating the copolymers include a substrate on which a film of the crosslinked epoxy-functional copolymer is disposed and target molecules bound to the copolymer film. The crosslinked polymer films are well-suited for use as scaffolds for target molecules in microarrays because they provide a high density of binding sites for the target molecules, are mechanically stable, and may be coated onto a wide range of substrates.