Simultaneous Determination of Ascorbic acid, Dopamine and Uric Acid at Aluminum Electrode Modified by Gold Nanoparticles and Cyestein

Dopamine (DA) is a kind of neurotransmitter in mammalian central nervous systems. Extreme abnormalities of DA levels cause symptoms of several diseases such as Parkinsonism [1]. The concentration of neurotransmitters in biological samples varies from one to other species, in a wide range from 10-6 to 10-3 M [2]. Hence the selectivity and sensitivity seemed important in the development of any procedure for the determination of dopamine in presence of ascorbic acid (AA) and uric acid (UA). Gold nanoparticles immobilized on amine-terminated self-assembled monolayers (SAM) on a polycrystalline Au electrode were successfully used for the selective determination of DA in the presence of ascorbate [3]. The poly (dimethylsiloxane) surface modification with gold nanoparticles used for the detection of DA and epinephrine [4]. Gold nanoparticles distributed 3-mercaptopropionic acid assembled on gold nanoparticle arrays were also reported [5].In this work, we are reporting Aluminum modified electrode by gold nanoparticle-cysteine for the simultaneous determination of DA, AA and UA. The CV and DPV were used to study the electrocatalytic behavior and the simultaneous determination of ternary mixtures of DA, AA and UA.