关键词: 离子溅射, 化学沉积, 金纳米电极, 活体分析, 多巴胺

Abstract: In vivo monitoring neurochemicals with microelectrode is invasive and the damage to brain tissue may inevitably cause disturbance signals physiologically to the measurement. It is of great importance to reduce the electrode size and to decrease the damage. This study demonstrates a novel nanoelectrode preparation methodology for in vivo monitoring dopamine (DA) fluctuation in the living brain of rats with high dependability. The fabrication process of the gold nanoelectrode involving a few minutes consists of only two steps: 1) growing gold nanoseeds on surface of tip of glassy capillary by ion sputtering; 2) wet depositing a continuous conductive gold film composed of gold nanoparticles by dipping the capillary with gold nanoseeds into a freshly mixed chloroauric acid and hydroxylamine hydrochloride for one minute. The tip size of the well-prepared gold nanoelectrode was 300 ~ 400 nanometers. The gold nanoelectrode was able to detect DA and showed a good linearity with the concentration of DA ranging from 1.0 to 56.0 μmol·L^-1 with a limit of detection as low as 0.14 μmol·L^-1 (S/N=3). Benefiting from the excellent electrochemical performance, the gold nanoelectrode was successfully employed for catecholamine release in striatum of living rat brain.

Key words: ion sputtering, wet deposition, gold nanoelectrode, in vivo, dopamine