iNAPO - Ion Conducting Nanopores in Polymer Foils Chemically Modified for Biomolecular Sensing
Proceedings of the World Congress on Recent Advances in Nanotechnology
In the present biomimetic approach, ion-conducting nanopores are fabricated in polymer foils and are chemically modified so that they can be used as the core of a biomolecular sensing system. The basic principles of fabrication and working mechanism of these nanosensors is described. Polyimide foils are irradiated at the heavy ion accelerator at GSI Helmholtz-Center in Darmstadt with a single ion of a heavy element such as gold. The ion is at such a high speed that it penetrates through the
... tes through the membrane in a straight line, forming a so-called latent ion damage track. This track is converted into a single conical nanopore via asymmetric chemical etching, with its smaller aperture being in the range of a few nanometers. At the surface of the nanopore a biorecognition unit (ligand) is immobilized which specifically fit to another molecule (receptor) to be analysed. Only with these analyte molecules recognition unit do react in a keylock principle. For sensing, the polymer foil with the nanopore is placed into an electrochemical cell with two compartments, with the foil acting as separation membrane. Each compartment contains an electrode dipped in electrolyte (potassium chloride) solution. When a potential is applied, an electric current flows through the nanopores. If analyte molecules (receptor) are present, they react with the immobilized ligand at the nanopore walls via specific ligand-receptor interaction, thus changing the transmembrane electrolyte current. Thus, the set-up works as a highly sensitive and specific nanosensor. Fabrication and working principle of this type of nanosensor is described. As an example, results on quantitative sensing of a protein are shown. As an outlook for development and application of this sensing principle, the iNAPO-project will be presented, run by a group of materials scientists, biologists, chemists, physicist and electrical engineers with the aim of creating new types of sensors based on bioinspired ion conducting nanopores.