Methods for detecting target analytes and enzymatic reactions

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 method of detecting a target analyte in a sample comprising:
 a) providing an array comprising:
 i) an array substrate, wherein said array substrate is other than a fiber optic bundle; and 
 ii) at least first and second sites wherein first and second reaction components are immobilized at said first and second sites, respectively; 
   b) contacting said array substrate with said sample; and   c) detecting a change in an optical property around at least said first site as an indication of the interaction between said target analyte and at least said first reaction component.   
     
     
         2 - 12 . (canceled) 
     
     
         13 . A method of detecting a target analyte in a sample comprising:
 a) providing an array comprising:
 i) an array substrate comprising discrete sites; and 
 ii) a population of microspheres comprising at least first and second subpopulations comprising:
 (a) first and second reaction components respectively; and 
 (b) a detection molecule; 
 
   b) contacting said array with said sample; and   c) detecting a change in an optical property around at least said first microsphere as an indication of the interaction between said target analyte and at least said first reaction component.   
     
     
         14 - 17 . (canceled) 
     
     
         18 . A method of detecting an enzymatic reaction comprising:
 a) providing an array comprising
 i) an array substrate comprising discrete sites; and 
 ii) a population of microspheres randomly distributed on said array substrate, said microspheres comprising at least one enzyme; 
   b) contacting said array with a sample comprising a target analyte, wherein said target analyte is an enzyme substrate;   c) monitoring a signal in a region surrounding said microspheres, whereby detection of said signal provides an indication of the reaction between said enzyme and said enzyme substrate.   
     
     
         19 - 25 . (canceled)