Patent ID: 7651863

Claim:
A method of analyzing a substance comprising: (a) providing a flexible structured substrate comprising: (i) a monolithic polymeric film comprising: a base having first and second opposed major surfaces, wherein at least a portion of the first major surface is at least partially defined by nanostructure, and wherein at least a portion of the first major surface is partially defined by a patterned microstructure outwardly extending from the base, wherein the nanostructure is at least partially encompassed within, or overlaps, the patterned microstructure, wherein the average height of the patterned microstructure is at least three times the average height of the nanostructure, and wherein the polymeric film, the base having first and second opposed major surfaces, the nanostructure, and the microstructure, constitute a monolithic polymeric unit; and (ii) a metal layer conformably disposed on at least a portion of the nanostructure; (b) providing an analyte in close proximity to at least a portion of the metal layer; and (c) observing a surface-enhanced optical property of the analyte.