Dresden 2009 – scientific programme

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BP: Fachverband Biologische Physik

BP 7: Poster I

BP 7.39: Poster

Monday, March 23, 2009, 17:45–20:00, P3

Fabrication of metallized solid state nanopores for single molecule experiments — •Ruoshan Wei, Daniel Pedone, Gerhard Abstreiter, and Ulrich Rant — Walter Schottky Institut, Technische Universität München, Deutschland

Nanopores in solid state membranes have emerged as powerful means to study single molecules. In translocation experiments, the trans-pore ionic current is monitored to detect the passage of individual molecules (nucleic acids or proteins). Engineered solid state pores hold considerable advantages over their biological counterparts with respect to stability and adjustability. With the aim of creating an electrically gateable pore which can be used to modulate the biomolecule translocation efficiency, we devised a novel concept where the nanopore is metallized on one side. Here we report on the device fabrication and electrical characterisation in aqueous electrolyte solution. Pores featuring diameters < 30 nm are fabricated in Si3N4 membranes by e-beam lithography. Subsequently, thin (< 20 nm) metal films of Pt or Au are evaporated on Ti adhesion layers. The surface roughness and film morphology are assessed for different deposition methods (e-beam vs. thermal evaporation). The trans-pore current as well as the device capacitances are studied using electrochemical impedance spectroscopy and FFT analysis of high-bandwidth current recordings. Within this framework, we investigate the reduction of current noise by surface passivation using silicone elastomers.