Patent ID: 7470379

Claim:
A composition comprising: an inorganic particle selected from the group consisting of a semiconductor nanocrystal and an inorganic colloid; a linking group, which has a distal end and a proximal end, the distal end being bound to an outer surface of the inorganic particle and the proximal end comprising a first charged or ionizable moiety; and a macromolecule including a first plurality of charged or ionizable moieties, wherein the first charged or ionizable moiety and the first plurality of charged or ionizable moieties electrostatically associate the inorganic particle with the macromolecule to form an ionic conjugate, the macromolecule being selected from the group consisting of a polypeptide, a polynucleotide, a nucleic acid, an antibody, a fusion protein, or an immunoglobulin G binding protein; wherein the first plurality of charged or ionizable moieties protrude away from the macromolecule.