Gold nanoparticles can easily be conjugated by more than one functional biomolecule, in particular if the nanoparticle is initially "naked" (ligand-free). Because of partial oxidation of gold surface atoms, the particle attracts electron donors, which adsorb and self-assemble. Any electron donative group works, but a terminal thiol group works best for anchoring on gold. Here, a cell penetrating peptide (positive backbone, animated green) and a targeting vector (nucleic acid, negative backbone, animated blue) are conjugated to the gold nanoparticle. This bivalent bioconjugate could be designed to penetrate into cells and target certain gene sequence of the chromosome inside the nucleus.
------: The projekt is supported by Deutsche Forschungsgemeinschaft (research see http://www.uni-due.de/barcikowski/forschen.htm).