The figure reports a comparison between PC-12 cells seeded on PEDOT:PSS film a, and bare glass b. In both cases the green fluorescence confirmed the presence of dopamine released locally at the cell membrane (in red), showing that dopamine is produced in vesicles in the PC-12 cells and then released. c, The viability of PC-12 cells was tested by staining live cells with calcein-AM (green) and dead cells with propidium iodide (red) for PEDOT:PSS electrodes coated with d, collagen IV and e, poly-L-lysine films. Both substrates exhibited good cell viability, with the collagen-IV coated film showing higher biocompatibility. For this reason, the collagen-IV coating was employed in all of the following experiments. f, Live/dead staining performed on PC-12 cells inside the microfluidic channel after performing repeated pulsed electrical measurements, showing no difference between cells cultured on PEDOT:PSS e, prior to and f, following electrical measurements, indicating no alteration of cell viability from the electrical measurements.