Microbial Potentiometric Sensors (MPS): Theory and Applications

Abstract:

Microbial Potentiometric Sensor (MPS) is an electrochemical sensor based on the measurement of the open-circuit potential between an indicator electrode(s) and a reference. The indicator electrode is exposed to the environment (water, sediments, soils) and the surface of the MPS becomes populated with an endemic biofilm. The potential measured is directly related to the biofilm populating the surface of the MPS. This has several significant advantages including no maintenance of the MPS is required. Biofouling the primary reason for the failure of most sensors, is in fact the active surface of the MPS.

The MPS measures the environment from the perspective of biofilms. The novel MPS measurement provides insights into aqueous, saturated and unsaturated environments. We will present example of the applications, both laboratory and field, of aquatic, saturated (sediments) and unsaturated environments. Because of the simplicity of the instrumentation and no requirement for maintenance of the sensors, the MPS is ideal for long-term monitoring of contaminated sites to determine the the effectiveness of a remedial, or the rate of natural zone depletion.