Differential Sensing With Biofet Sensors

A method, comprising:

• forming first and second sensing regions on first and second field effect transistors (FET) sensors, respectively;
• depositing a first capture reagent on the first sensing region;
• depositing, on the second sensing region, a second capture reagent different from the first capture reagent;
• forming a fluid delivery system configured to introduce a target solution over the first and second sensing regions;
• and
• coupling the first and second FET sensors to a readout circuit configured to determine a presence of one or more target analytes in the target solution.

A method, comprising:

• forming first, second, and third field effect transistors (FET) sensors comprising first, second, and third channel regions, respectively;
• forming, on the first channel region, a first sensing region bound to a first capture reagent;
• forming, on the second channel region, a second sensing region bound to a second capture reagent different from the first capture reagent;
• and
• forming, on the third channel region, a third sensing region that is free of capture reagents.