Recombinant maxi-K channels on transistor, a prototype of iono-electronic interfacing

We report on the direct electrical interfacing of a recombinant ion channel to a field-effect transistor on a silicon chip. The ion current through ac tivated maxi-K-Ca channels in human embryonic kidney (HEK293) cells gives r ise to an extracellular voltage between cell and chip that controls the ele ctronic source-drain current. A comparison with patch-clamp recording shows that the channels at the cell/chip interface are fully functional and that they are significantly accumulated there. The direct coupling of potassium channels to a semiconductor on the level of an individual cell is the prot otype for an iono-electronic interface of ligand-gated or G protein-coupled ion channels and the development of screening biosensors with many transfe cted cells on a chip with a targe array of transistors.