US Patent 7446870 - Sensor for classifying nanoparticle sizes

http://www.freepatentsonline.com/7446870.html

This patent from Siemens teaches forming surfaces by molecular imprinting having different sized pores matching with corresponding nanoparticles that are desired to be detected and classified. Such a technique could potentially be useful to form multi-color LEDs using nanocrystals having emission frequencies that correspond to the nanocrystals diameter. Claim 1 reads:

1. A method for verification of nanoparticles, said method comprising:

providing a plurality of sensor areas on which the nanoparticles to be verified accumulate when said nanoparticles are present, and

monitoring the characteristics of the plurality of sensor areas with respect to one parameter which varies on the basis of the accumulation of the nanoparticles,

wherein the plurality of sensor areas are made available, and are sensitive to nanoparticles of different sizes and the plurality of sensor areas have a specificity to specific size classes of nanoparticles.