Abstract: Element tags based on novel metal-polymer conjugates are provided for elemental analysis of analytes, including ICP-MS. A polymer backbone is functionalized to irreversibly bind metals that are selected prior to use by the user. The polymer is further functionalized to attach a linker which allows for attachment to antibodies or other affinity reagents. The polymer format allows attachment of many copies of a given isotope, which linearly improves sensitivity. The metal-polymer conjugate tags enable multiplexed assay in two formats: bulk assay, where the average biomarker distribution in the sample is diagnostic, and single cell format to distinguish a rare (for example a diseased) cell in a complex sample (for example, blood).

Abstract: The present invention provides a method of surface passivation of colloidal nanocrystalline materials using a ligand exchange process in which quantum nanoparticles of pre-selected size and shape has polymer multidentate ligands bound at the surface of the nanocrystals for stabilizing quantum size-dependent properties of nanocrystals and providing colloidal stability of the nanoparticles in solvents.