Amperometric Lactate Biosensor Based on Carbon Paste Electrode Modified with Benzo[ c ]cinnoline and Multiwalled Carbon Nanotubes

Amperometric lactate biosensor based on a carbon paste electrode modified with benzo[ c ]cinnoline and multiwalled carbon nanotubes is reported. Incorporation of benzo[ c ]cinnoline acting as a mediator and multiwalled carbon nanotubes providing a conduction pathway to accelerate electron transfer due to their excellent conductivity into carbon paste matrix resulted in a high performance lactate biosensor. The resulting biosensor exhibited a fast response, high selectivity, good repeatability and storage stability. Under the optimal conditions, the enzyme electrode showed the detection limit of 7.0×10 −8  M with a linear range of 2.0×10 −7  M–1.1×10 −4  M. The usefulness of the biosensor was demonstrated in serum samples.