Functionalized, probe-containing, latex nanospheres

Synthesis of surface-functionalized, probe-containing latex nanospheres is described. Approximately 40,000 probe ions may be encapsulated in a nanosphere of 50 nm diameter. The probe may be a radionuclide or a lanthanide with long-lived fluorescence. Alternatively, a "cargo" of pharmaceutical interest may be used. The surface of each nanosphere contains thousands of acid groups which may be functionalized for subsequent attachment to biomolecules such as antibodies. Functionalized nanospheres have been successfully coupled to a tobacco virus.