Abstract: In an example method, a grafting solution is applied to a patterned substrate using a liquid-phase thin-film deposition technique. The patterned substrate includes a lane surrounded by, or a plurality of depressions separated by interstitial regions; and a polymer in the lane or in each of the plurality of depressions. The polymer is functionalized with a first click reaction moiety. The grafting solution includes a solvent; a polymer matrix material dissolved in the solvent; and primers of a primer set dissolved in the solvent, each of the primers being terminated with a second click reaction moiety. The applied grafting solution is dried. During drying, a solid polymer matrix is formed and at least some of the primers attach to the polymer i) via the first and second click reaction moieties and ii) in at least a portion of the lane or in at least some of the plurality of depressions.

Abstract: An example of a flow cell includes a substrate; a plurality of reactive regions spatially separated from one another across the substrate; and a plurality of independently removable coatings respectively positioned over each of the plurality of reactive regions. Each of the plurality of reactive regions includes a polymeric hydrogel layer; and a reactive entity attached to the polymeric hydrogel layer.

Abstract: In an example method, a water-soluble protective coating solution is applied over a bonding region and either i) a patterned region of a patterned structure or ii) a lane region of a non-patterned structure. The patterned region includes depressions having at least a polymeric hydrogel therein, and interstitial regions separating the depressions. The lane region includes a lane having at least the polymeric hydrogel therein. The water-soluble protective coating solution is dried to form a solid coating or a gel coating over the bonding region and over either i) the patterned region or ii) the lane region. Portions of the solid coating or the gel coating are selectively removed from the bonding region while leaving other portions of the solid coating or the gel coating over either i) the patterned region or ii) the lane region.