Robust Thermally Oxidized ZnO Nanowire Electrodes for High-Fidelity Intracellular Recording and Pharmacological Assessment

High-fidelity intracellular electrophysiological recording of cardiomyocytes is fundamental to cardiac research and drug development, which is still hindered by technical challenges in achieving stable, long-term intracellular access. Here, we introduce a platform based on thermally oxidized ZnO nanowire electrodes (TONEs), which directly integrate nanowires in patterned microelectrodes via scalable thermal oxidation. The three-dimensional nanointerface facilitates minimally invasive electroporation for high-quality intracellular action potential recordings compared with conventional planar electrodes. Moreover, the platform supports stable, repeated, and on-demand intracellular recordings over consecutive days from the same cell. Furthermore, the characteristic changes in action potential induced by Class Ia and Class Ib antiarrhythmic drugs is precisely detected, which validates the sensitivity of this platform for pharmacological assessment. This work indicates that the TONEs platform can serve as a robust and reproducible approach for cardiac electrophysiology, toxicology, and pharmacology research.