Systems, methods, and devices for selective capture and release of target particles, e.g., living cells, from liquid samples, e.g., blood, are provided. The particle capture systems include a substrate; a first layer of gelatin bound to the substrate by physical adsorption, wherein the gelatin is functionalized with a plurality of first members of a binding pair; a second layer of gelatin wherein the gelatin is functionalized with a plurality of the first members of the binding pair and the second layer is bound to the first layer via a plurality of second members of the binding pair that are associated with the first members of the binding pair on both the first and the second layers; and a plurality of nanostructures bound to the second members of the binding pair and to one or more particle-binding moieties that selectively bind to the target particles.