Abstract: Device and methods for controlling pH or ionic gradient comprising a multisite array of feedback electrode sets comprising electrodes and pH sensing elements. The electrodes can include a reference electrode, counter electrode, and a working electrode. The device and methods iteratively select an amount of current and/or voltage to be applied to each working electrode, apply the selected amount of current and/or voltage to each working electrode to change pH of a solution close to the working electrode, and measure the signal output of the sensing element. The multisite array can include feedback and non-feedback electrode sets.

Abstract: Closed-loop systems and methods for controlling pH. The system includes a working electrode, a counter electrode, a reference electrode, a first ion-sensitive field-effect transistor (ISFET), a second ISFET, and an electronic controller. The working electrode, the counter electrode, the reference electrode, and a first sensing terminal of the first ISFET are immersible in an active solution. A second sensing terminal of the second ISFET is immersible in a reference solution. The electronic controller is configured to apply a first amount of current or voltage to the working electrode and determine a differential voltage between the first ISFET and the second ISFET. The electronic controller is also configured to set a second amount of current or voltage to reduce a difference between the differential voltage and a target voltage. The electronic controller is further configured to apply the second amount of current or voltage to the working electrode.

Abstract: Provided is a method for monitoring a change of ion strength in a sample solution by a closed-loop device that provides continuous cycling of electrochemical pH modulation between pre-defined pH values. In particular, the change of ion strength may be induced by a chemical reaction and may ultimately alter the electrical control parameters of the closed-loop device. By measuring such electrical control parameters, the degree and progress of the underlying chemical reaction may be monitored.

Abstract: Closed-loop systems and methods for controlling pH. The system includes a working electrode, a counter electrode, a reference electrode, a first ion-sensitive field-effect transistor (ISFET), a second ISFET, and an electronic controller. The working electrode, the counter electrode, the reference electrode, and a first sensing terminal of the first ISFET are immersible in an active solution. A second sensing terminal of the second ISFET is immersible in a reference solution. The electronic controller is configured to apply a first amount of current or voltage to the working electrode and determine a differential voltage between the first ISFET and the second ISFET. The electronic controller is also configured to set a second amount of current or voltage to reduce a difference between the differential voltage and a target voltage. The electronic controller is further configured to apply the second amount of current or voltage to the working electrode.

Abstract: Device and methods for controlling pH or ionic gradient comprising a multisite array of feedback electrode sets comprising electrodes and pH sensing elements. The electrodes can include a reference electrode, counter electrode, and a working electrode. The device and methods iteratively select an amount of current and/or voltage to be applied to each working electrode, apply the selected amount of current and/or voltage to each working electrode to change pH of a solution close to the working electrode, and measure the signal output of the sensing element. The multisite array can include feedback and non-feedback electrode sets.