Ceramic-based multisite microelectrode array for rapid choline measures in brain tissue

A ceramic-based multisite microelectrode array to measure choline in vivo in brain tissues is described. The microelectrodes were linear to 200μM choline (R²=0.999±0.001) with a detection limit of approximately 0.4μM (S/N of 3) in both single microelectrode and self-referencing amperometric recording modes. The 90% rise time of the sensor was 1.4s, allowing for rapid measures of choline. Good selectivity (>300:1) was observed over interferents such as ascorbic acid, uric acid, and DOPAC in the single microelectrode mode. However, a self-referencing recording mode was needed to remove potassium-evoked dopamine signals in rat striatum. In vivo measurements of choline in the rat brain are presented.