Selective and Rapid Biosensor Integrated into a Commercial Hand‐Held Instrument for the Measurement of Ammonium Ion in Sewage Effluent

Abstract

A disposable biosensor for ammonium ions in sewage effluent was developed and based on a screen‐printed carbon electrode coated with the enzyme glutamate dehydrogenase, 2‐oxoglutarate, and NADH. This rapid and selective amperometric biosensor is capable of detecting NH₄ ⁺ in sewage effluent at concentrations in the range 1–10 ppm. The biosensor was developed as a disposable, reagentless device incorporated into a fully automated, hand‐held instrument that can be used away from the laboratory. This low cost, commercially available system permits the measurement of NH₄ ⁺ in effluent samples in only 5 min and 20 s without any pretreatment. The results obtained correlated well with the standard laboratory method, used by the Environment Agency.

Keywords:

• Screen‐printed electrode
• amperometric biosensor
• ammonium ion
• sewage effluent

The authors wish to thank Mr Terry Long and the Environment Agency, UK, for funding. They are also grateful to Mr Wayne Civil, National Laboratory Service, Starcross Laboratory, Exeter, for providing data on sewage effluent samples.