Recording Spikes Activity in Cultured Hippocampal Neurons Using Flexible or Transparent Graphene Transistors
Authors: Dipankar Kalita
Zheng Han
Cécile Delacour
Farida Veliev
Vincent Bouchiat
Anne Briançon-Marjollet
Journal: Frontiers in Neuroscience (2017)
Discipline: NEUROSCIENCE & BEHAVIOR
Keywords: bioelectronics; electrophysiology; graphene; hippocampal neurons; neural interfaces
Affiliations: Institut Néel, Centre National de la Recherche Scientifique and Université Grenoble AlpesGrenoble, France., Grenoble Alpes, HP2 Laboratory, Institut National de la Santé et de la Recherche Médicale U1042Grenoble, France.

Abstract:  The emergence of nanoelectronics applied to neural interfaces has started few decades ago, and aims to provide new tools for replacing or restoring disabled functions of the nervous systems as well as further understanding the evolution of such complex organization. As the same time, graphene and other 2D materials have offered new possibilities for integrating micro and nano-devices on flexible, transparent, and biocompatible substrates, promising for bio and neuro-electronics. In addition to many bio-suitable features of graphene interface, such as, chemical inertness and anti-corrosive properties, its optical transparency enables multimodal approach of neuronal based systems, the electrical layer being compatible with additional microfluidics and optical manipulation ports. The convergence of these fields will provide a next generation of neural interfaces for the reliable detection of single spike and record with high fidelity activity patterns of neural networks. Here, we report on the fabrication of graphene field effect transistors (G-FETs) on various substrates (silicon, sapphire, glass coverslips, and polyimide deposited onto Si/SiO2 substrates), exhibiting high sensitivity (4 mS/V, close to the Dirac point at VLG &lt; VD) and low noise level (10-22 A2/Hz, at VLG = 0 V). We demonstrate the in vitro detection of the spontaneous activity of hippocampal neurons in-situ-grown on top of the graphene sensors during several weeks in a millimeter size PDMS fluidics chamber (8 mm wide). These results provide an advance toward the realization of biocompatible devices for reliable and high spatio-temporal sensing of neuronal activity for both in vitro and in vivo applications. 

Retracted: No

PubPeer comments:
 Figure 1G looks very similar to Figure 1C from: Sensing ion channel in neuron networks with graphene field effect transistors, Veliev et al., 2018, , 2D Mater. 5 (2018) 045020![file] , 
 Hello Henneguya Cutanea Indeed data are identical and for a good reason : these two papers are depicting two different aspects (general characterization in paper one, more in-depth physical effect in paper 2) from the same batch of samples. So I do not see the problem. , 
 Dear Prof. Bouchiat, First of all many thanks for your reply and clarification. Your comment, as you say, completely clarifies the misunderstanding. However, the reason I did not know that the batch of samples in the two papers is the same comes from the fact that in the 2nd and more recent paper (2D materials) this fact is not mentioned (correct if I am wrong, please). Indeed, the fabrication of the device and the characterisation have a full paragraph dedicated (in both Results and Supplementary Materials and Methods), leading the reader to think that this data is new and innovative. Thanks again for your time. , 
 #3 Both papers relate innovative elements. If you read the papersthoroughly you will see that the AFM pictures you mention are control experiments to check sample cleanliness . Therefore they are not directly related to the concepts scientific content developed in each paper. ,