Determination of Dopamine with Poly(L-argenine)/Gold Nanoparticles Modified Electrode

A novel poly(L-argenine)/gold nanoparticles modified electrode (AuNPs/GCE) was fabricated by electropolymerization of poly(L-argenine)/AuNPs/GCE which was prepared by AuNPs/GCE.The modified electrode was characterized by atomic force microscopy.The electrochemical behavior of dopamine on the poly(L-argenine)/AuNPs/GCE was studied.It was found that the poly(L-argenine)/AuNPs/GCE exhibited strong electrocatalytic activity to the oxidation of dopamine in phosphate buffer solution of pH 5.7,and the redox reaction of dopamine was a quasi-reversible process controlled mainly by adsorption.Linear relationship between values of oxidation peak current and concentration of dopamine was kept in the range of 8.0×10-7-1.0×10-4mol·L-1,with detection limits (3S/N) of 1.0×10-7mol·L-1.The proposed method was applied to the analysis of samples of dopamine injection,giving values of recovery in the range of 96.5%-104%.Precision of the method was tested at the concentration level of 3.0×10-5mol·L-1 dopamine solution for 7 determination,with value of RSD of peak current of 2.6%.