The present invention generally provides multicomponent articles of manufacture and methods of making them. In its broadest aspect, the invention provides a multicomponent article that includes a
diffraction grating-based encoded element, wherein the encoded element includes an optical substrate having at least one surface, and an optical coding element; and a substance disposed on at least a portion of the surface of the substrate. The optical substrate may be made from a wide variety of materials. Importantly the multicomponent article may be a
reagent particle wherein the substance includes a
reagent. The
reagent may be chosen from a wide range of biological macromolecules and oligomeric molecules, from any organic chemical or
inorganic chemical compound including pharmaceutical agents and candidate pharmaceutical agents, modifications of any of them, and from any microbiological entity, a
cell, and similar entities. In another aspect the invention provides a coded reagent
library including a plurality of reagent particles described herein the preceding paragraphs. In another aspect the invention provides a method of preparing a multicomponent article including the steps of providing a
diffraction grating-based encoded element, and binding a substance to a surface of said optical substrate. The invention also provides a method of preparing a coded reagent
library. Additionally the invention provides a method of synthesizing a
polynucleotide reagent on a multicomponent article.