Electrochemical pre-concentration for improved detection of gaseous species in water

A deployable sensor for detection of a gaseous analyte in water, the deployable sensor comprising:

• a first chamber, a second chamber and a third chamber;
• an ion exchange membrane configured such that ions would pass through the ion exchange membrane between the first chamber and the second chamber;
• a gas permeable membrane configured such that dissolved gas can pass through the gas permeable membrane between the second chamber and the third chamber;
• an electrical source configured to provide a voltage between a first electrode in the first chamber and a second electrode in the second chamber such that
• i) an analyte-ion corresponding to the gaseous analyte is generated in the first chamber, and
• ii) the gaseous analyte is generated in the second chamber from analyte-ions that have passed through the ion exchange membrane;
• wherein the third chamber includes a solution configured to generate the analyte-ion from gaseous analyte that has passed through the gas permeable membrane;
• an electrical sensor configured to detect a third concentration of the analyte-ion in the third chamber;
• wherein the electrical sensor is configured to have an electrical property that is responsive to the third concentration of the analyte-ion in the third chamber.