Label-free immobilization of nano-particles on silicon based electrodes for single-biomolecule studies

Dielectrophoresis (DEP) is an established method for the spatial manipulation of microscopical particles. We demonstrate the temporal and permanent immobilization of polystyrene nanoparticles and protein molecules with sizes ranging from 4 nm to 500 nm. For this, regular arrays of silicon based nanoelectrodes were developed with tip diameters of 10 nm and 50 nm. No chemical modifications of molecules, particles or surfaces were needed. This opens up potentially important applications of DEP in biosensing and cell research.