Highly selective and sensitive determination of dopamine using Nafion coated microelectrode arrays

The present study concerns methodological issue of electrochemical recordings using Nafion-coated microelectrode arrays fabricated by MEMS technology for voltammetric and amperometric measurements of dopamine (DA). The properties of Nafion-coated different temperature dried microelectrodes were determined by cyclic voltammetry. The electrochemical characteristics of the 120 degrees C dried Nafion-coated microelectrode for measures of dopamine and ascorbic acid (AA) were studied by chronoamperometry. These studies showed that the 120 degrees C dried Nafion-coated microelectrode had better recording properties: enlarged electrochemical signal for DA and high selectivity for DA versus AA. The linear response was obtained in the range of 0.1 to 50 microM with a low detection limit. The modified microelectrode arrays providing 30 microm diameter multiple sites showed the capability to simultaneously detect DA from cells, neurons and brain slices.