Nanopore/electrode structures for single-molecule biosensing

Biological and solid-state nanopores have recently attracted much interest as ultrafast DNA fragment sizing and sequencing devices. Their potential however goes far beyond DNA sequencing. In particular, nanopores offer perspectives of single-molecule (bio)sensing at physiologically relevant concentrations, which is key for studying protein/protein or protein/DNA interactions. Integration of electrode structures into solid-state nanopore devices moreover enables control and fast switching of the pore properties, e.g. for active control of biopolymer transport through the nanopore. We present some of recent work in this area, namely the fabrication and characterization of nanopore/electrode architectures for single-(bio)molecule sensing. Specifically, we introduce a new technique to fabricate ultra-small metal nanopores with diameters smaller than 20 nm based on ion current feedback (ICF) controlled electrodeposition. It offers precise control of the pore conductance, is easily multiplexed, and can be extended to a wide range of different metals.