US Patent 7943552 - Quantum dot nanocrystal inventory control

http://www.freepatentsonline.com/7943552.html

This patent from M.I.T. has priority going back to 1998 and includes some basic claims to using semiconductor quantum dots for inventory control. Claim 1 reads:

1. A library of compounds, wherein each compound in the library is bound to an individual support, each support having associated therewith more than one population of semiconductor nanocrystals, each population having a distinct characteristic spectral emission, wherein each compound is attached to the support during a synthesis sequence, wherein each nanocrystal comprises a Group II-VI semiconductor, a Group III-V semiconductor, or a Group IV semiconductor selected from a group consisting of ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, MgTe, GaN, GaP, GaAs, GaSb, InP, InAs, InSb, AlP, AlSb, AlS, Ge, or Si.