A prototype protein field-effect transistor

Electrical conduction in a macroscopic assembly of apoferritin, a non-redox protein, has been characterized using a three-terminal prototype device. Our result shows an ohmic conduction near zero bias. The ohmic conduction can be controlled using an electric field applied to the protein assembly via the gate terminal of the device. The transconductance of the protein device shows a highly nonlinear dependence on the gate voltage. The transconductance curve indicates that the device has the attributes of an n-channel metal-oxide-semiconductor field-effect transistor with electrons as charge carriers. The input/output dynamic response of the device has been demonstrated.