Toward encoding combinatorial libraries: Charge-driven microencapsulation of semiconductor nanocrystals luminescing in the visible and near IR

Polymer microspheres coded either with a single luminescence color or with multiple colors of controlled emission intensity ratios were fabricated by the charge-driven encapsulation of water-soluble CdTe nanocrystals luminescing in the visible and near infrared (IR). Encapsulation occurred by pumping of negatively charged nanocrystals into the interior of specially designed polymer spheres consisting of a polymer shell and a core containing the solution of a positively charged polyelectrolyte, or vice versa.