Abstract: Small organometallic probes are disclosed which include a core of metal atoms bonded to organic moieties. The metal atoms are gold, silver, platinum, palladium, or combinations thereof. In one embodiment, a multifunctional organometallic probe is disclosed which includes a core of metal atoms surrounded by a shell of organic moieties covalently attached to the metal atoms, a fluorescent molecule, e.g., fluorescein, covalently attached to one of the organic moieties, and a targeting molecule, e.g., an antibody, covalently attached to another of the organic moieties. In another embodiment, a small metal cluster of palladium or platinum is disclosed in which the central metal core comprises platinum or palladium in which the central metal core is from about 1.8 to 3.6 nm in diameter and contains about 309 to about 2,057 metal atoms. This metal core has 1,10-phenanthroline organic moieties covalently attached to the metal core. A process for making this palladium and platinum cluster compound is also disclosed.

Abstract: Small organometallic probes comprise a core of metal atoms bonded to organic moieties. The metal atoms are gold, silver, platinum, palladium, or combinations thereof. In one embodiment, a multifunctional organometallic probe comprises a core of metal atoms surrounded by a shell of organic moieties covalently attached to the metal atoms, a fluorescent molecule, e.g., fluorescein, covalently attached to one of the organic moieties, and a targeting molecule, e.g., an antibody, covalently attached to another of the organic moieties.