▎ 摘　　要

The authors describe a three-dimensional (3D) structure composed of graphene and DNA for use in a voltammetric dopamine (DA) sensor. The material was deposited on a gold electrode, and the enhanced charge-transfer performance and deposition of DNA were confirmed by electrochemical analysis. Atomic force microscopy shows the graphene-DNA composite to have been assembled on the modified gold electrode. The modified gold electrode possesses excellent electrocatalytic activity for determination of DA, best at a working voltage of 0.1 V (vs. SCE). Ascorbic acid does not interfere. Response to DA is linear in the 0.1 to 100 mu M concentration range, with a 30 nM detection limit even in the presence of 1.0 mM of ascorbic acid.