Sensitive determination of dopamine on poly(aminobenzoic acid) modified electrode and the application toward an experimental Parkinsonian animal model

Recent research on the pathology and treatment of Parkinson's disease (PD) necessitates the development of methods for analysis of dopamine (DA), an electroactive substance whose content reduces in patients with PD. The concentration variation of dopamine in an experimental Parkinsonian animal model and a treatment model was studied in this paper. For the purpose of detecting dopamine sensitively, a poly(para-aminobenzoic acid) (P-pABA) electrochemically modified glassy carbon electrode was prepared. The electrochemical behavior of the modified electrode was studied by cyclic voltammetry. Under optimum conditions, the P-pABA modified electrode showed high sensitivity to DA oxidation. Coupled with high-performance liquid chromatography, the modified electrode was utilized to detect dopamine in rat brain dialysate with the linear range over three orders of magnitude and the detection limit of 2.0 × 10^-8 mol l^-1 (S/N = 3). By treatment with reserpinum, an experimental Parkinsonian animal model was produced. Levodopa (L-dopa) and sodium nitroprusside (SNP) were used as drugs for treatment PD in this work. The dopamine level in PD model was only 22.4% that of the control one. PD rats could recover after therapy of L-dopa or SNP and the dopamine level increased sixfold compared with those not treated with drugs.