Methylthiouracil-modified Carbon Paste Electrode as a New Voltammetric Sensor Based on a 1,4-Michael Addition Reaction for Detection of Dopamine

摘要

A sensitive dopamine sensor was constructed based on the modified carbon paste electrode with methylthiouracil as a nucleophile in the 1,4-Michael addition reaction. An ECE mechanism was suggested for dopamine oxidation at the modified electrode. Design of experiments was used in the optimization of variables. Under the optimum conditions, calibration graph was linear in the range of 0.20-15.0 mu M with a detection limit of 73 nM. The relative standard deviations (n=5) for 0.50 mu M of dopamine was 3.83%. The selectivity of the sensor was also studied. The developed sensor was applied for analysis of pharmaceutical and biological samples.