Ever since x-ray diffraction first revealed protein structures, biological molecules have fascinated scientists with their perfectly engineered, elegant designs able to perform functions well beyond the reach of conventional devices. Inevitably, researchers have dreamed of developing a functional interface between living organisms and electronic circuits, enabling better, more specific diagnostics and prosthetics that could be controlled by direct input from the peripheral nervous system or the brain. The idea of using microelectronics to probe the activity of biological systems originated with early work on capacitive stimulation of cells.1 More recently, neuronal control of siliconnanowire (SiNW) transistor arrays has been demonstrated.2 Yet the clear mismatch in scale between cellular machinery and electronic circuitry made the early interfaces crude and inefficient. The discovery of carbon nanotubes and SiNWs has given researchers a new opportunity to construct electronic interfaces comparable in size to biological molecules. We have shown how the electrical response of a nanowire transistor can be controlled by an ion-channel protein placed in close proximity to the nanowire, and even that voltage applied by the device can control those biological channels. Our versatile, self-assembled nanoplatform integrates a fieldeffect transistor (FET) with membrane-bound proteins that mediate the majority of signaling in living systems.3 A cell membrane—its outer layer—is made up of phospholipids, molecules with a hydrophilic head and two hydrophobic tails that arrange themselves into a two-layered sheet (bilayer) with their tails pointing inwards when exposed to water. Proteins embedded in the membrane can act as ‘pores’ or channels, allowing certain signaling ions to pass through the cell’s outer layer. Inhibitors can block the pore and prevent other ions from passing through. Our nanoplatform is a 1D lipid-bilayer membrane covering a nanowire template.4 The lipid bilayer closely mimics a Figure 1. (a) Device schematics showing an ion channel embedded in the lipid bilayer covering the silicon nanowire (SiNW). S and D denote source and drain electrodes and Vg is the applied gate voltage. (b) SiNW normalized conductance, G/G0, recorded as the solution’s pH was changed from 6 to 9 for the uncoated (blue) and coated NW (black), and the coated-NW device incorporating Alamethicin pores (red). (c) Time traces of a similar experiment recorded at a gate bias of 0.15V. ( c © 2009 The National Academy of Sciences. Reproduced with permission.5)