Individually addressable multichannel nanoelectrodes reveal spatially resolved functional heterogeneity of vesicles...

Nanoelectrodes are powerful tools for high-resolution electrochemical measurements, yet a long-standing limitation has been the inability to perform simultaneous, spatially resolved measurements across multiple domains within a single confined system. Here we develop an individually addressable multichannel nanoelectrode platform that preserves nanoscale spatial resolution while enabling independent and parallel electrochemical recording. The platform supports batch fabrication of nanoelectrodes with either hollow or filled architectures, providing precise geometric control for applications ranging from confined intracellular environments to open electrochemical interfaces, as validated by electron microscopy, voltammetry, and simulations. Applied to single living cells, hollow multichannel electrodes enable minimally disruptive, region-resolved intracellular recording from nuclear-adjacent and membrane-proximal domains, providing direct quantitative evidence for functional heterogeneity of vesicle populations. These findings uncover a previously inaccessible mechanistic link between subcellular vesicle organization and secretion efficiency, with direct implications for how neuroendocrine and neuronal cells achieve rapid yet regulated chemical signaling.