Patterned flow-cells useful for nucleic acid analysis

A method of making a nucleic acid array, comprising

• (a) providing a surface comprising metal regions and interstitial regions, the interstitial regions having a composition that differs from the metal regions, wherein a continuous gel layer coats the surface across the metal regions and the interstitial regions;
• (b) contacting the continuous gel layer with a fluid comprising analytes;
• and
• (c) selectively modifying the portions of the gel layer that coat the interstitial regions compared to the portions of the gel layer that coat the metal regions,
• thereby attaching the analytes to the gel layer, wherein a greater amount of the analytes from the fluid attach to portions of the gel layer that coat the metal regions than the amount of analytes that attach to portions of the gel layer that coat the interstitial regions.

A method of preparing a surface, comprising

• (a) providing a surface comprising metal regions and interstitial regions, the interstitial regions having a composition that differs from the metal regions;
• (b) contacting the surface with a fluid comprising a polymerizable material, wherein the fluid coats the surface across the metal regions and the interstitial regions;
• and
• (c) polymerizing the polymerizable material, thereby forming a continuous gel layer that coats the surface across the metal regions and the interstitial regions, wherein portions of the gel layer that coat the metal regions have greater mass than portions of the gel layer that coat the interstitial regions.