On the Electrocatalytic Action Toward Dopamine at the Na2mnt-Self-Assembled Monolayer Modified Gold Electrode

Na2mnt-self-assembled monolayer modified gold electrode (mnt-SAM/Au) was prepared by immersion of the polished and cleaned Au-electrode into solution of 5 mmol·L-1 cis-disodium-1,2-dicyanoethylene-1,2-dithiolate (also named as dicyanodithiolene and abbr. as Na2mnt) for 24 h. Electrochemical behavior of the modified electrode was studied and it was found that the reversibility of the radox of dopamine (DPM) at the mnt-SAM/Au modified electrode was improved significantly; an increase of peak current was observed; the redox process was controlled by diffusion; and no adsorption of DPM and no contamination were found on the modified electrode. As a biomatter of DPM, a buffer medium of PBS with pH 7.00 was chosen for its detection. Under the optimum conditions, linear relationship between values of concentration of DPM in the range of 4.0×10-6-2.0×10-4mol·L-1 and the respective peak current (i/nA) was found.