Label-free optical sensing and characterization of biomolecules by d8 or d10 metal complexes

Abstract

The present invention provides a composition for detecting and/or characterizing a multiple-charged biomolecule comprising a charged d<8> or d<10> metal complex, wherein the metal complex electrostatically binds to the multiple-charged biomolecule to induce aggregation and self-assembly of the metal complex through metalmetal interactions, pp interactions, or a combination of both interactions. The present invention further provides assay methods and kits for label-free optical detection and/or characterization of biomolecules carrying multiple charges, e.g., single-stranded nucleic acids, polyaspartate, polyglutamate, using a composition comprising a charged d<8> or d<10> metal complex.