Fabrication of a template-synthesized gold nanorod-modified electrode for the detection of dopamine in the presence of ascorbic acid

Gold nanorods (GNRs) with suitable aspect ratio were synthesized with a template technique and then dispersed in a saturated sodium citrate solution by ultrasonication to form a GNR suspension. A GNR-modified electrode was fabricated using the GNR suspension. The oxidation of dopamine at the GNR/GC electrode exhibited surprisingly high electrocatalytic activity and adsorption-controlled characteristics. Square-wave voltammetry was used to detect dopamine. At the GNR/GC electrode, the linear concentration range of DA is from 1 x 10(-8) M to 1 x 10(-7) M and the detection limit (s/n = 3) is as low as 5.5 x 10(-9) M. The current sensitivity is 3.280 mu A/mu M, and 1000-fold ascorbic acid (AA) cannot interfere with the determination of DA. All these performances are greatly superior to those of the bare GC electrode. (C) 2007 Elsevier B.V. All rights reserved.