Abstract: A smart sensor system is provided which uses a monitoring electrode to produce a calibration output that can be used in-situ and in real-time to monitor and address reference electrode drift and to provide information regarding sensor operation. The monitoring electrode uses a redox chemistry that is either a non-active redox species that is not sensitive to changes in a solution being tested/monitored or a redox active species that sets a pH of the local environment proximal to the electrode when the electrode is contacted with a test and/or reference solution. The smart sensor system includes at least one of a solid-state electrochemical sensor; a glass electrode, a reduction oxidation sensor; and/or a glucose sensor and/or a sensor to monitor constituent parts of the solution composition.

Abstract: A calibration electrode for calibrating a reference system of an electrochemical sensor, such as a potentiometric sensor or an ion selective electrode. The calibration electrode has an active surface comprising redox functionalities. The redox functionalities set the pH of a reference solution proximal to the calibration electrode. A voltammetric signal is applied to the calibration electrode to produce a response that is determined by the set pH. The response of the calibration electrode to the voltammetric signal is used to calibrate/adjust a reference potential produced by a reference electrode of the reference system of the electrochemical sensor. This calibration corrects the detrimental effect of reference electrode drift.

Abstract: A working electrode for an electrochemical pH sensor includes a active redox species that is configured to contact a low buffering capacity/low ionic strength solution, either directly or via a polymer layer, and to generate a redox potential that depends upon the pH/hydrogen ion concentration of the solution. The active redox species comprises a 5 or a 6 member ring substituted with an oxygen group atom and a further carbon ring coupled with a hydrogen atom, the active redox species being configured to provide for hydrogen bonding between the hydrogen atom and the substituted oxygen group atom.

Abstract: An online calibration system for an electrochemical sensor. The calibration system comprises a calibration electrode coupled with a redox species, where the redox species is configured to control a pH of a reference solution local to the calibration electrode, such that when a voltammetric signal is applied to the calibration electrode the output generated from the calibration system is determined by the local environment pH. The output signal from the calibration system is used to calibrate a reference potential generated by a reference system of the electrochemical sensor to correct for drift in the reference potential when the electrochemical sensor is being used. The calibration electrode may be disposed in a reference cell of the electrochemical sensor.

Abstract: A reference system for an electrochemical or ion selective sensor where a reference electrode is coupled with a redox active species and the redox active species is configured to set a pH value of a local environment of a low buffer/low buffering capacity analyte media proximal to the reference electrode. The pH value of the low buffer/low buffering capacity proximal to the reference electrode may be controlled to a pH value at least one pH unit above or below pH 7. The voltammetric response of the redox active species is used as a reference and/or reference signal for the electrochemical or ion selective sensor.

Abstract: A smart sensor system is provided which uses a monitoring electrode to produce a calibration output that can be used in-situ and in real-time to monitor and address reference electrode drift and to provide information regarding sensor operation. The monitoring electrode uses a redox chemistry that is either a non-active redox species that is not sensitive to changes in a solution being tested/monitored or a redox active species that sets a pH of the local environment proximal to the electrode when the electrode is contacted with a test and/or reference solution. The smart sensor system includes at least one of a solid-state electrochemical sensor; a glass electrode, a reduction oxidation sensor; and/or a glucose sensor and/or a sensor to monitor constituent parts of the solution composition.

Abstract: An electrochemical pH sensor for measuring pH in a low buffer and/or low ionic strength analyte where the electrochemical pH sensor comprises an electrode coupled with a phenolic redox species and the chemistry of the redox species provides for hydrogen bonding to one or more sulphur atoms of the redox species.

Abstract: A calibration electrode for calibrating a reference system of an electrochemical sensor, such as a potentiometric sensor or an ion selective electrode. The calibration electrode has an active surface comprising redox functionalities. The redox functionalities set the pH of a reference solution proximal to the calibration electrode. A voltammetric signal is applied to the calibration electrode to produce a response that is determined by the set pH. The response of the calibration electrode to the voltammetric signal is used to calibrate/adjust a reference potential produced by a reference electrode of the reference system of the electrochemical sensor. This calibration corrects the detrimental effect of reference electrode drift.

Abstract: An online calibration system for an electrochemical sensor. The calibration system comprises a calibration electrode coupled with a redox species, where the redox species is configured to control a pH of a reference solution local to the calibration electrode, such that when a voltammetric signal is applied to the calibration electrode the output generated from the calibration system is determined by the local environment pH. The output signal from the calibration system is used to calibrate a reference potential generated by a reference system of the electrochemical sensor to correct for drift in the reference potential when the electrochemical sensor is being used. The calibration electrode may be disposed in a reference cell of the electrochemical sensor.

Abstract: A voltammetric reference control system for generating a reference signal for an electrochemical sensor. The electrochemical sensor may comprise a voltammetric sensor, a potentiometric sensor, an amperometric sensor, an ion selective sensor and/or the like that is designed to be used in solutions, such as water, seawater, saline solutions and/or the like. The voltammetric reference control system generates a reference potential that does not drift and/or does not require calibration during operation of the electrochemical sensor.

Abstract: An online calibration system for an electrochemical sensor. The calibration system comprises a calibration electrode coupled with a redox species, where the redox species is configured to control a pH of a reference solution local to the calibration electrode, such that when a voltammetric signal is applied to the calibration electrode the output generated from the calibration system is determined by the local environment pH. The output signal from the calibration system is used to calibrate a reference potential generated by a reference system of the electrochemical sensor to correct for drift in the reference potential when the electrochemical sensor is being used. The calibration electrode may be disposed in a reference cell of the electrochemical sensor.

Abstract: A reference system for an electrochemical or ion selective sensor where a reference electrode is coupled with a redox active species and the redox active species is configured to set a pH value of a local environment of a low buffer/low buffering capacity analyte media proximal to the reference electrode. The pH value of the low buffer/low buffering capacity proximal to the reference electrode may be controlled to a pH value at least one pH unit above or below pH 7. The voltammetric response of the redox active species is used as a reference and/or reference signal for the electrochemical or ion selective sensor.

Abstract: An electrochemical pH sensor for measuring pH in a low buffer and/or low ionic strength analyte where the electrochemical pH sensor comprises an electrode coupled with a phenolic redox species and the chemistry of the redox species provides for hydrogen bonding to one or more sulphur atoms of the redox species.