Electrochemical and Catalytic Investigations of Homocysteine Using Multiwall Carbon Nanotubes Paste Electrode as a Sensor and Methyldopa as a Mediator

A sensitive and selective electrochemical sensor for the determination of homocysteine (HCy) was developed using a modified multiwall carbon nanotubes pasteelectrode (MWCNTPE) in the presence of methyldopa (MDOP) as a mediator. This modified electrode showed very efficiency electrocatalytic activity for the anodicoxidation of HCy. Under the optimized conditions, the electrocatalytic peak current showed linear relationship with HCy concentration in the range of 0.1 – 800.0 μmol L-1 with a detection limit of 0.06 μmol L-1 HCy. The relative standard deviations for sixsuccessive assays of 1.0 and 15.0 μmol L-1 HCy were 2.1% and 2.6%, respectively. Finally, the modified electrode was examined as a selective, simple and precise new electrochemical sensor for the determination of HCy in serum and urine samples.

Keywords:

Homocysteine , Carbon paste electrode , Multiwall carbon nanotubes , Sensor