A method for the intracranial delivery of reagents to voltammetric recording sites

► Double barrel electrodes combine detection and reagent delivery in a single device. ► This design enables electrode optimization and highly localized reagent delivery. ► However, capillary tips leak reagents at physiologically relevant concentrations. ► Segmenting the reagent solution from the tip solution prevents premature delivery. ► Pressure ejections mix reagent into the tip solution, enabling reagent delivery.