Chemical sensing capability of MEMS implantable multichannel neural microelectrode arrays

The capability of sensing catecholamine fluctuations in the brain is useful to determine how neurostimulation - both chemical and electrical - can affect catecholamine release and uptake. Here we report preliminary results on two multichannel neural probes capable of sensing dopamine through chronoamperometry methods. With a 16-channel microelectrode array and five-channel Michigan puffer probe with a microfluidic channel, we found that a 5-cycle dip coating process of Nafion, an ion-selective polymer, optimized sensitivity to dopamine and selectivity over ascorbic acid. In addition, through fluorescent microscopy, we have shown the suitability of Nafion as a "biocompatible" material for chronically implanted microelectrode probes. These findings support the ongoing work to develop chronic implantable chemical sensors.