Biosensor having ultra fine fiber
A high-sensitivity field effect transistor using as a channel ultrafine fiber elements such as carbon nanotube, and a biosensor using it. The field effect transistor comprises a substrate, a source electrode and a drain electrode arranged on the substrate, a channel for electrically connecting the source electrode with the drain electrode, and a gate electrode causing polarization due to the movement of free electrons in the substrate. For example, the substrate has a support substrate consisting of semiconductor or metal, a first insulating film formed on a first surface of the support substrate, and a second insulating film formed on a second surface of the support substrate, the source electrode, the drain electrode, and the channel arranged on the first insulating film, the gate electrode disposed on the second insulating film.
1. A biosensor device including a biosensor device body and an element section which is attachable to and detachable from the biosensor device body, wherein said element section includes a field effect transistor comprising:
a substrate having a first insulating film, a second insulating film and a support substrate composed of a semiconductor material or metal, the support substrate being sandwiched between said first insulating film and said second insulating film;
a source electrode and a drain electrode disposed on the first insulating film;
a channel electrically connecting said source electrode and said drain electrode, and including an ultra fine fiber, said channel being disposed on said first insulating film;
a gate electrode capable of causing a polarization due to a movement of free electrons in said substrate and capable of controlling an electric current flowing through said channel, said gate electrode being arranged on said second insulating film; and
molecules immobilized on said second insulating film, said molecules capable of capturing a detection target substance being sandwiched between said second insulating film and said gate electrode, wherein when said element section is mounted to said biosensor device body, the electric current flows through said channel, and said gate electrode controls the electric current flowing through said channel.
2. A biosensor device including a biosensor device body and an element section which is attachable to and detachable from said biosensor device body, wherein said element section includes a field effect transistor comprising:
a substrate, having a support substrate composed of a semiconductor material or metal, and a first insulating film formed on a first plane of said support substrate;
a source electrode and a drain electrode disposed on said substrate;
a channel electrically connecting said source electrode and said drain electrode and including an ultra fine fiber;
a gate electrode capable of causing a polarization due to a movement of free electrons in said substrate and capable of controlling an electric current flowing through said channel; and
molecules immobilized directly on said gate electrode and capable of capturing a detection target substance, wherein when said element section is mounted to said biosensor device body, the electric current flows through said channel, and said gate electrode controls the electric current flowing through said channel, said source electrode, said drain electrode, said channel and said gate electrode being arranged on a same surface of said first insulating film.