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: An agile nucleic acid sensor includes: a DNA switch; an analysis substrate in electrostatic communication with the DNA switch and that produces a biomarker electrical signal; a transduction member that receives the biomarker electrical signal and produces a transduction signal; a sensor counter electrode in electrical communication with and capacitively coupled to the analysis substrate and that receives a counter electrode voltage; a sensor reference electrode in electrical communication and capacitively coupled to the analysis substrate and that produces a feedback signal based on electrical interactions with a composition that is in fluid contact with the feedback signal and the analysis substrate; and a voltage follower in electrical communication with the sensor counter electrode and the sensor reference electrode and that receives the feedback signal from the sensor reference electrode and produces the counter electrode voltage for the sensor counter electrode based on the feedback signal.

Abstract: A biomarker signal amplifier amplifies chemical analyte binding and includes: a surface strand disposed on an analysis substrate and including an exchange region; a particle strand hybridized to the surface strand in an absence of a chemical analyte that preferentially hybridizes to the exchange region as compared with the particle strand, and the particle strand is dissociated from the surface strand when the surface strand is in a presence of the chemical analyte; and a reporter particle attached to the particle strand and disposed proximate to the analysis substrate when the particle strand is hybridized to the surface strand in absence of the chemical analyte and that changes the electrical potential of the analysis substrate depending on whether the particle strand is hybridized to the surface strand.

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.