Electrical interfacing of neurotransmitter receptor and field effect transistor
Department of Membrane and Neurophysics, Max Planck Institute for Biochemistry, D 82152, Martinsried/Munich, Germany
* e-mail: email@example.com
Accepted: 7 April 2009
Published online: 10 June 2009
The interfacing of a ligand-gated ion channel to a transistor is studied. It relies on the transduction of ion current to a voltage in a cell-transistor junction. For the first time, a genetically modified cell is used without external driving voltage as applied by a patch-pipette. Using a core-coat conductor model, we show that an autonomous dynamics gives rise to a signal if a driving voltage is provided by potassium channels, and if current compensation is avoided by an inhomogeneous activation of channels. In a proof-of-principle experiment, we transfect HEK293 cells with the serotonin receptor 5-HT3A and the potassium channel Kv1.3. The interfacing is characterized under voltage-clamp with a negative transistor signal for activated 5-HT3A and a positive signal for activated Kv1.3. Without patch-pipette, a biphasic transient is induced by serotonin. The positive wave is assigned to 5-HT3A receptors in the free membrane that drive a potassium outward current through the adherent membrane. The negative wave is attributed to 5-HT3A receptors in the adherent membrane that are activated with a delay due to serotonin diffusion. The implementation of a receptor-cell-transistor device is a fundamental step in the development of biosensors that combine high specificity and universal microelectronic readout.
PACS: 87.85.dh Cells on a chip – / 85.30.Tv Field effect devices – / 87.16.Vy Ion channels –
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2009