Spatially Controlled Assembly of Nanomaterials at the Nanoscale

A molecular monolayer of 4-nitrothiophenol on gold electrodes is reduced electrochemically when its nitro groups are converted into amino groups by potentiometric scans. The protonated amine with its NH3+ functions can be employed to induce the self-assembly of gold nanoparticles at the surface of the electrodes. The electrochemical reaction and the induced assembly process can be controlled at the nanoscale level on the electrodes with a high degree of selectivity. The technology opens up the possibility of fabricating complex multi-nanomaterial nanostructures on the basis of a two-step electrochemical assembly process.