Arrays of microparticles and methods of preparation thereof

Abstract

This invention provides high unit density arrays of microparticles and methods of assembling such arrays. The microparticles in the arrays may be functionalized with chemical or biological entities specific to a given target analyte. The high unit density arrays of this invention are formed on chips which may be combined to form multichip arrays according to the methods described herein. The chips and/or multichip arrays of this invention are useful for chemical and biological assays.

1 - 23 . (canceled) 
     
     
         24 . A process for directly depositing beads on a surface of a semiconductor wafer or portion thereof to form a bead array, said process comprising adding a solution of beads to the surface of a patterned semiconductor wafer having a plurality of retention zones, each retention zone comprising structures therein for restraining beads on the wafer, and mechanically agitating the solution to induce the beads to settle into the structures, wherein the wafer may subsequently be broken into a plurality of individual chips. 
     
     
         25 . The process of  claim 24 , wherein the structures for restraining the beads comprise recesses. 
     
     
         26 . The process of  claim 25 , wherein the recesses are sized such that the opening diameter of a recess at its surface is smaller than the diameter of the recess at its bottom. 
     
     
         27 . The process of  claim 24 , wherein the structures for restraining the beads comprise blocks, posts, or bumps. 
     
     
         28 . The process of  claim 24 , wherein the structures for restraining the beads are sized such that their dimensions are greater than the average diameter of the beads. 
     
     
         29 . The process of  claim 28 , wherein the structures for restraining the beads are sized such that they may each accommodate only one bead. 
     
     
         30 . The process of  claim 24 , wherein the structures for restraining the beads are sized such that they accommodate more than one bead. 
     
     
         31 . The process of  claim 24 , wherein the structures for restraining the beads are sized such that the height of the highest point of the structures is 0.5 to 1.5 times the average diameter of the beads. 
     
     
         32 . The process of  claim 31 , wherein the highest point of the structures for restraining has a height of 1 and ⅓ times the average diameter of the beads. 
     
     
         33 . The process of  claim 31 , wherein the structures for restraining the beads are sized such that, when the beads are settled into the structures, the beads' highest edges are below the highest point of the structures for restraining. 
     
     
         34 . The process of  claim 24 , wherein the beads are attached to the surface prior to breaking the wafer into a plurality of individual chips. 
     
     
         35 . The process of  claim 34 , wherein the surface attachment is by covalent bonds, van der Waals, electrostatic, gravitational, magnetic forces, or combinations thereof.