A semiconductor nanocrystal compound is described capable of linking to an affinity
molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting
electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting
electromagnetic radiation-when excited by an electromagnetic radiation source or
a particle beam; and (2) at least one linking agent, having a first portion linked
to the semiconductor nanocrystal and a second portion capable of linking to an
affinity molecule. The compound is linked to an affinity molecule to form a semiconductor
nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure
to excitation energy will excite the semiconductor nanocrystal in the probe causing
the emission of electromagnetic radiation. Further described are processes for
respectively: making the luminescent semiconductor nanocrystal compound; making
the semiconductor nanocrystal probe; and using the probe to determine the presence
of a detectable substance in a material.
