3D Plasmonic Nanoelectrodes for Cells Investigations and Neural Interfaces

Figure 1. Left and central panels: 3D plasmonic nanoelectrodes combined with CMOS technology. Right panel: the same technology can be combined with microfluidic chips to exploit the inner hollow nanochannel passing through the plasmonic nanotubes

We presented a manufacturing process capable of defining three-dimensional hollow nanostructures made of noble metals of various shapes and spatial arrangements [1]. The process is robust and enables to structure nanomaterials into unconventional geometries whose characteristic length varies from hundreds of nm (visible range) up to few tenths of mm (mid-infrared). In addition we showed that the presented antennas are connected by an uninterrupted metallic layer that does not prevent their plasmonic functioning hence they can work as plasmonic antennas and nanoelectrodes at the same time. Therefore, the fabrication process is compatible with CMOS technology, thus enabling the fabrication of CMOS micro-electrode array with three-dimensional nanoelectrode coming out of the CMOS surface [2]. We report on our latest results on the investigation of intracellular action potential of cultured neuronal network, as well as the spectroscopic investigations (Raman Scattering) of the distribution of biomolecules located in close proximity of the cell membrane or inside the cell. In addition, when the devices are fabricated on suspended membranes, a plasmonic nano-channel can achieved through the whole antenna. We demonstrated that it can work as an optical nanocavity far below the Abbe diffraction limit (see figure, right panel). Such a nano-channel can be combined with a microfluidic device for administrating the desired molecules to living cells cultured on the device. These devices are also very promising for a wide range of applications spanning from optoelectronics, nanoelectrodes for photo-electrochemical catalysis, photovoltaic, and solar to fuel energy conversion.

[1] F. De Angelis et al., 3D Hollow Nanostructures as Building Blocks for Multifunctional Plasmonics. Nano Letters 2013, 13, 3353-3358.

[2] Micha E. Spira & Aviad Hai. Multi-electrode array technologies for neuroscience and cardiology. Nature Nanotechnology 8, 83–94 (2013)

Acknowledgements. This research received fundings from the European Research Council under the European Union`s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. [616213], CoG: Neuro-Plasmonics.

francesco.deangelis@iit.it