Amperometric determination of l-dopa by nickel hexacyanoferrate film modified gold nanoparticle graphite composite electrode

Surface modification of graphite electrode with nickel hexacyanoferrate (NiHCF) film through 2-mercaptoethylamine (MEA) capped gold nanoparticle (GNP) was achieved by a novel fabrication approach. The NiHCF modified electrode exhibits a distinct pair of redox peaks corresponding to anodic and cathodic reactions of hexacyanoferrate (II/III) of NiHCF with a formal potential of 0.33 V versus SCE. l-Dopa, is a potential chemotherapeutic drug used for the treatment of a neurodegenerative disease like Parkinson's disease (PD). l-Dopa was successfully determined by NiHCF modified electrode in the concentration range of 0.82 μM to 2.5 mM with a good sensitivity of 0.363 μA/μM. A reduction in overpotential of 200 mV with a detection limit of 0.53 μM was obtained. Determination of l-dopa in commercial tablets was also investigated by the proposed sensor.