A vertically integrated nanoscale tipped microprobe intracellular electrode array

Here we report integration of nanoscale tipped 120-μm-long vertical microprobe electrode (NTE) array and intracellular recordings using a gastrocnemius muscle of a mouse. The tip diameter and curvature radius of the NTE was < 200 nm, respectively, and the controlled height of the exposed tip section was 4 μm. The impedance of the fabricated NTE exhibited 3.1 MΩ at 1 kHz in saline, with the output/input signal amplitude ratio of 50%. The penetrated NTE into the muscle of a mouse detected the resting membrane potentials with the amplitude of ∼ −200 mV, indicating that the NTE device detected intracellular signals from the mouse's muscle. Although we have demonstrated the intracellular recording capability using a muscle, such nanoscale electrodes with a high aspect ratio can be used for multisite intracellular recordings within numerous neuronal tissues including brain slice.