Research neuronal signaling is the subject of a very large community, but progresses face a dense multi-scale dynamics involving signaling at the molecular, cellular and large neuronal network levels. Whereas the brain capabilities are most likely emerging from large neuronal networks, available electrophysiological methods limit our access to single cells and typically provides only a fragmented observation, on limited spatial/temporal scales. Therefore, broadening the spectrum of scales for observing neuronal signaling within large neuronal networks is a major challenge that can revolutionize our capability of studying the brain and its physio-pathological functions, as well as of deriving bio-inspired concepts to implement artificial system based on neuronal circuits. We propose the development of an innovative electro-plasmonic multifunctional platform that by combining different methodologies emerging from distant fields of Science and Technology will provide a radically new path for real time neurointerfacing at different scale levels:1. The molecular scale: 3D plasmonic nanoantennas will give access to information at molecular level by means of enhanced spectroscopies with particular regard of time resolved Raman scattering.2. The single-neuron scale within neuronal networks: by both in-cell and extra-cell couplings with 3D nanostructures which work at the same time as plasmonic antennas and CMOS 3D nanoelectrodes.3. The scale of large neuronal networks: by CMOS high-density electrode arrays for spatially and temporally resolving neuronal signaling form thousands of measuring sites.This is achieved by exploiting an innovative nanofabrication method able to realize 3D nanostructures which can work at the same time as plasmonic nanoantennas and as nanoelectrodes. These structures will be integrated on CMOS multi-electrode arrays designed to manage multiscale measurements from the molecular level up to network level on several thousand of measurement sites.