Abstract: A closed-loop controlled chemical apparatus includes: a compound sensor including: an analyte sensor and that: produces, by the analyte sensor, a voltage signal; a reference sensor in electrical communication with the analyte sensor; a transistor including a gate terminal such that a drain current of the transistor is maintained at a constant value and operated at an optimal transduction condition of peak sensitivity and minimum noise of the transistor; a feedback controller in electrical communication with the transistor and that: receives a transduction signal; determining a deviation of the transduction signal from a setpoint, the setpoint determined by transfer characteristics of the transistor; produces the feedback control signal that minimizes the deviation of the transduction signal from the based on a control model; and communicates the feedback control signal to the reference sensor for suppression of electrical noise fluctuations in the closed-loop controlled chemical apparatus.

Abstract: A charge detector includes: a charge sensor that senses a charged analyte and produces a charge signal in response to contact with the charged analyte; a transducer in electrical communication with the charge sensor and that: receives the charge signal from the charge sensor, receives a feedback control signal; and produces a transduction signal in response to receipt of the charge signal and the feedback control signal; and a sensitivity controller in electrical communication with the transducer and that: receives the transduction signal from the transducer; produces the feedback control signal in response to receipt of the transduction signal from the transducer; and produces a charge readout in response to receipt of the transduction signal from the transducer.

Abstract: A closed-loop controlled chemical apparatus includes: a compound sensor including: an analyte sensor and that: produces, by the analyte sensor, a voltage signal; a reference sensor in electrical communication with the analyte sensor; a transistor including a gate terminal such that a drain current of the transistor is maintained at a constant value and operated at an optimal transduction condition of peak sensitivity and minimum noise of the transistor; a feedback controller in electrical communication with the transistor and that: receives a transduction signal; determining a deviation of the transduction signal from a setpoint, the setpoint determined by transfer characteristics of the transistor; produces the feedback control signal that minimizes the deviation of the transduction signal from the based on a control model; and communicates the feedback control signal to the reference sensor for suppression of electrical noise fluctuations in the closed-loop controlled chemical apparatus.

Abstract: A charge detector includes: a charge sensor that senses a charged analyte and produces a charge signal in response to contact with the charged analyte; a transducer in electrical communication with the charge sensor and that: receives the charge signal from the charge sensor, receives a feedback control signal; and produces a transduction signal in response to receipt of the charge signal and the feedback control signal; and a sensitivity controller in electrical communication with the transducer and that: receives the transduction signal from the transducer; produces the feedback control signal in response to receipt of the transduction signal from the transducer; and produces a charge readout in response to receipt of the transduction signal from the transducer.