Site-specific presentation of single recombinant proteins in defined nanoarrays

The authors describe the deposition of single biomolecules on substrates at defined spacing by pure self-assembly. The substrate is equipped with an array of 8 nm large gold particles which form the template for biomolecule binding. The authors verified the successful binding of single biomolecules via specific antibody labeling and imaging by fluorescence microscopy. Scanning force microscopy provided evidence that every gold nanoparticle of the pattern is occupied by at least one biomolecule. Furthermore, gold conjugated secondary antibodies in combination with scanning electron microscopy proved that at least 75% of the nanoparticles carried only one active biomolecule. The precision given by such surface densities is molecularly defined and such considerably higher than in any other case reported so far.