Target analyte sensors utilizing microspheres

Abstract

A microsphere-based analytic chemistry system and method for making the same is disclosed in which microspheres or particles carrying bioactive agents may be combined randomly or in ordered fashion and dispersed on a substrate to form an array while maintaining the ability to identify the location of bioactive agents and particles within the array using an optically interrogatable, optical signature encoding scheme. A wide variety of modified substrates may be employed which provide either discrete or non-discrete sites for accommodating the microspheres in either random or patterned distributions. The substrates may be constructed from a variety of materials to form either two-dimensional or three-dimensional configurations. In a preferred embodiment, a modified fiber optic bundle or array is employed as a substrate to produce a high density array. The disclosed system and method have utility for detecting target analytes and screening large libraries of bioactive agents.

1 . A composition comprising:
 a) a substrate with a surface comprising discrete sites; and   b) a population of microspheres distributed on said sites.   
     
     
         2 - 18 . (canceled) 
     
     
         19 . A method of determining the presence of a target analyte in a sample comprising:
 a) contacting said sample with a composition comprising:
 i) a substrate with a surface comprising discrete sites; and 
 ii) a population of microspheres comprising at least a first and a second subpopulation each comprising:
 1) a bioactive agent; and 
 2) an optical signature capable of identifying said bioactive agent; 
 
 wherein said microspheres are distributed on said surface such that said discrete sites contain microspheres; and 
   b) determining the presence or absence of said target analyte.   
     
     
         20 - 23 . (canceled)