Shown below is a chemical-sensing field effect transistor (FET) in the absence o
ID: 495615 • Letter: S
Question
Shown below is a chemical-sensing field effect transistor (FET) in the absence of an applied gate potential. Explain how a chemical-sensing FET generates a response to an analyte by arranging the following statements in order. The sample is introduced to the gate. A voltage is applied between the source and the drain, but no current flows. A current flows between the source and drain as a conductive channel forms. The current flowing between the source and the drain changes. A positive potential is applied to the gate, which attracts electrons from the base. Analyte adsorbs onto the chemically-sensitive gate, resulting in a change in potential of the gate. A potential is applied to the external circuit to return the current to its original value.Explanation / Answer
1.A voltage is applied between the source and the drain, but no current flows.
2.the sample is introduce to the gate
3.a positive potential is applied to the gate, which attracts electrons from the base
4.the current flowing between the source and the drain changes
5.a current flows between the source and drain as a conductive channel forms
6.analyte adsorbs onto the chemically-sensitive gate, resulting in a change in potential of the gate.
7.a potential is applied to the external circuit to return thecuttent to its original value.