Advanced Biomimetic Nanostructured Microelectrode Arrays for Enhanced Extracellular Recordings of Enteric Neurons

Abstract

Microelectrode surfaces covered with nanostructures derived from components of extracellular matrix, such as collagen fibers, have shown immense beneficial effects in promoting neuronal growth and cellular signaling. Synthetic nanostructures mimicking the features of biological nanostructures with durable conductive materials could promote the cell adhesion on microelectrode surfaces by providing topographical cues and simultaneously improve the charge transfer properties by reducing its global impedance. Therefore, an advanced nanostructuring method mimicking the structural and organizational features of natural collagen fibers onto metallic microelectrode surfaces has been presented here, which is adapted from previous technological achievements of the group and is based on nanoimprint lithography and gold electroplating. Surface characterization methods reveal an increase in surface area between 20% and 68% on the microelectrodes fabricated with two different nanostructure heights. Impedance spectroscopy measurements reveal reduction in impedance magnitude (at 1 kHz) between 22% and 41%, depending upon the nanostructure height and density on the microelectrode, which should subsequently modulate its charge transfer properties for biosensing application. Cell adhesion analysis performed with seal impedance measurements reveals a tighter coupling of enteric neurons on the nanostructured microelectrodes. Finally, extracellular recordings from enteric neurons exhibit a significant improvement in spike detection properties of the nanostructured microelectrodes.

Implantable neural electrodes: from preparation optimization to application

“…For the use of specific materials (such as PEDOT:PSS and CNT, silk fibroin composite, etc.) or special structures to prepare nerve electrodes that can improve neural signal transmission while supporting neuronal elongation and cell adhesion, 79,181,182 some adhesion and proliferation tests will be conducted on nerve cells and electrodes. Combined with the use of scanning electron micrographs (SEM) to characterize the electrode morphology, it can more effectively display the impact of the material surface on cells.…”