| 摘要 |
The invention relates to a device and a method for measuring small voltages and potentials on biological, chemical, and other samples. The device comprises at least one field effect transistor with a source, a drain, and a gate which contacts the sample and is insulated from the conductive channel of the field effect transistor by means of a gate dielectricum. The device also comprises means for applying a voltage between the source and the drain and means for applying a bias voltage to the gate. According to the invention, the gate dielectricum has at least one attachment point in the interior of the gate dielectricum, said attachment point being capable of collecting charge carriers from the channel and conversely dispensing the charge carriers to the channel. By using such an attachment point to permanently exchange charge carriers with the channel in a statistic manner, the attachment point superimposes the current flowing through the channel, and thus through the transistor, with a telegraph modulation signal, the characteristic time constants of which can be used as a measurement signal for the potential or voltage of the sample instead of the drain current average time value used until now. In this manner, a greater amount of the measured information is evaluated with respect to the desired result, thereby substantially improving the sensitivity and precision of the measurement. |
