Development of In-situ pH Sensor Using ISFET
A0115Kiminori Shitashima Environmental Science Department, Central Research Institute of Electric Power Industry (CRIEPI)
A0116Masanori Kyo Marine Technology Department, Japan Marine Science and Technology Center (JAMSTEC)
A0117Yuichi Koike Research Institute of Innovative Technology for the Earth (RITE)
A0118Hideaki Henmi Mebius Advanced Technology
The development of in-situ chemical sensor plays a key role in
understanding of chemical and biological processes in the ocean. In
deep-sea hydrothermal systems, in-situ mapping and long term
monitoring of the chemical parameters in hydrothermal plumes are the
most efficient methods for trying to understand hydrothermal discharge.
In-situ chemical sensors are necessary for these purposes.
Hydrothermal plumes show pH anomalies because carbon dioxide and/or
hydrogen sulfide-rich fluids are mixed into the ambient sea water. We
developed an in-situ pH sensor for mapping and long term monitoring of
pH anomalies at hydrothermally active areas. The in-situ pH sensor
employs an ion sensitive field effect transistor (ISFET) as a pH
electrode, and the Cl-ion selective electrode (Cl-ISE) as a reference
electrode. The ISFET is a semiconductor that can measure ion
concentration in aqueous phase and has a quick response (within a
nanosecond), high accuracy (0.01~0.005pH)and pressure-resistant.