A nitrite microsensor for profiling environmental biofilms

TY - JOUR

T1 - A nitrite microsensor for profiling environmental biofilms

AU - De Beer, Dirk

AU - Schramm, Andreas

AU - Santegoeds, Cecilia M.

AU - Kühl, Michael

PY - 1997/3/1

Y1 - 1997/3/1

N2 - A highly selective liquid membrane nitrite microsensor based on the hydrophobic ion-carrier aquocyano-cobalt(III)-hepta(2-phenylethyl)-cobrynate is described. The sensor has a tip diameter of 10 to 15 μm. The response is log-linear in freshwater down to 1 μM NO2- and in seawater to 10 μM NO2-. A method is described for preparation of relatively large polyvinyl chloride (PVC)-gelled liquid membrane microsensors with a tip diameter of 5 to 15 μm, having a hydrophilic coating on the tip. The coating and increased tip diameter resulted in more sturdy sensors, with a lower detection limit and a more stable signal than uncoated nitrite sensors with a tip diameter of 1 to 3 μm. The coating protects the sensor membrane from detrimental direct contact with biomass and can be used for all PVC-gelled liquid membrane sensors meant for profiling microbial mats, biofilms, and sediments. Thanks to these improvements, liquid membrane sensors can now be used in complex environmental samples and in situ, e.g., in operating bioreactors. Examples of measurements in denitrifying, nitrifying, and nitrifying/denitrifying biofilms from wastewater treatment plants are shown. In all of these biofilms high nitrite concentrations were found in narrow zones of less than 1 mm.

AB - A highly selective liquid membrane nitrite microsensor based on the hydrophobic ion-carrier aquocyano-cobalt(III)-hepta(2-phenylethyl)-cobrynate is described. The sensor has a tip diameter of 10 to 15 μm. The response is log-linear in freshwater down to 1 μM NO2- and in seawater to 10 μM NO2-. A method is described for preparation of relatively large polyvinyl chloride (PVC)-gelled liquid membrane microsensors with a tip diameter of 5 to 15 μm, having a hydrophilic coating on the tip. The coating and increased tip diameter resulted in more sturdy sensors, with a lower detection limit and a more stable signal than uncoated nitrite sensors with a tip diameter of 1 to 3 μm. The coating protects the sensor membrane from detrimental direct contact with biomass and can be used for all PVC-gelled liquid membrane sensors meant for profiling microbial mats, biofilms, and sediments. Thanks to these improvements, liquid membrane sensors can now be used in complex environmental samples and in situ, e.g., in operating bioreactors. Examples of measurements in denitrifying, nitrifying, and nitrifying/denitrifying biofilms from wastewater treatment plants are shown. In all of these biofilms high nitrite concentrations were found in narrow zones of less than 1 mm.

UR - http://www.scopus.com/inward/record.url?scp=0031030476&partnerID=8YFLogxK

M3 - Journal article

AN - SCOPUS:0031030476

SN - 0099-2240

VL - 63

SP - 973

EP - 977

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

IS - 3

ER -