Integrated electrochemical neurosensors

Arrays of silicon neurosensors have been fabricated in our group for detection of both electrical signals and neurotransmitter levels in human neuron cultures. Neurochemical sensing of dopamine and its metabolites is provided by voltammetry. Passive neurochemical arrays have been tested in living human neuron cultures throughout a study period of seventy-five days. Calibration curves for dopamine taken in culture media with equipment optimized for the sensors suggests detection limits for dopamine below 100nM. To improve response, prototype devices incorporating active circuitry were developed. These active devices were formed by post-processing standard CMOS die fabricated through the MOSIS service, to form the sensor-specific features. We also describe a fully-differential potentiostat which has been developed for implantable biological applications and briefly describe future directions for our work