Biosensor Based on Electrocodeposition of Carbon Nanotubes/Polypyrrole/Laccase for Neurotransmitter Detection

A new biosensor has been developed by a simple electrocodeposition of multiwalled carbon nanotubes (MWCNT), polypyrrole (PPy) and laccase (Lac) on the platinum (Pt) electrode surface. The neurotransmitter biosensor was applied to the detection of dopamine in urine samples using differential pulse voltammetry (DPV). The Pt/MWCNT/PPy/Lac biosensor exhibited a detection limit of 0.14 mu M, which is an adequate level for monitoring dopamine in urine. Reproducibility and repeatability values of 2.9% and 1.7%, respectively, were obtained compared to the conventional procedure. The proposed biosensor was successfully applied in the determination of dopamine in urine, and the obtained results were in full agreement with those from the HPLC procedure.