Related Experiment Video
Updated: Jun 28, 2026

The Use of a β-lactamase-based Conductimetric Biosensor Assay to Detect Biomolecular Interactions
Published on: February 1, 2018
Interferences in a polypyrrole-based amperometric ammonia sensor
I Lähdesmäki1, W W Kubiak, A Lewenstam
1Process Chemistry Group, c/o Laboratory of Analytical Chemistry, Abo Akademi University, FIN-20500 Turku-Abo, Finland.
Abstract:
The main focus of this article is on the interferences encountered when an amperometric ammonia sensor is used in matrices that are typical in clinical samples. The sensor is tested in presence of such interferences and ways to suppress them by sensor modification are presented. Two modification procedures are evaluated by comparing the stabilities, detection limits and signal-to-noise ratios of such sensors. Further, the issue of the ammonia-sensing mechanism of the polypyrrole electrode is addressed. Evidence is shown that a mobile counterion may be required for proper sensor operation. Such evidence supports the idea that polypyrrole undergoes a reversible redox reaction when ammonia is detected at submillimolar concentrations.
Related Concept Videos
Amperometry: Overview
Potentiometry: Membrane Electrodes
Atomic Absorption Spectroscopy: Interference
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS): Interferences

