Development and first results of a new mesoporous microelectrode DO-sensor

A new dissolved oxygen (DO) sensor for marine application was developed and first tests in the field were carried out. The sensor uses a mesoporous microelectrode as the sensing element that has an inherently fast response and an increased resistivity to bio-fouling due to the properties of the electrode material, mesoporous platinum. Introduction of a cleaning cycle, where the potential applied to the electrode is altered, allows the elimination of material build up at the electrode surface as well as the reconditioning of the electrode-surface, thus minimising drift and the effect of bio-fouling. Mesoporous microdisc electrodes ranging between 10 and 50 μm diameter have been tested. The sensor has been adapted to operate on a CTD system. Results of two test cruises are presented, showing that although the general sensor performance is good further work has to be done to exploit the inherently fast response of the microelectrodes