US Patent 7452565 - Microparticle immobilization using nanoparticles

http://www.freepatentsonline.com/7452565.html

In order to enhance the adhesion of microbeads used in bioassays to a substrate this patent teaches using silica nanoparticles to fill in gaps formed between the microbeads and wells in the substrate. Claim 1 reads:

1. A method of affixing an array of microparticles in a series of recesses in a substrate surface, comprising:

placing microparticles in said series of recesses in a manner such that one microparticle resides in any one recess;

placing a nanoparticle suspension on the substrate surface over said series of recesses having microparticles therein;

incubating the nanoparticle suspension with the microparticle containing substrate whereby numerous nanoparticles get deposited and wedged between the microparticle and the walls of the recess in which it resides.