Journal: Frontiers in Neuroscience

Article Title: Bidirectional Modulation of Neuronal Cells Electrical and Mechanical Properties Through Pristine and Functionalized Graphene Substrates

doi: 10.3389/fnins.2021.811348

Figure Lengend Snippet: Fabrication and characterization of pSLG and fSLG. (A) Scheme of the graphene transfer process from copper to glass exploiting an electrochemical delamination procedure: (i) CVD-grown single-layer graphene on copper; (ii) deposition of a supportive PMMA film; (iii) electrochemical delamination; (iv) free-standing graphene/PMMA layers; (v) transfer on glass; (vi) dissolution of the sacrificial PMMA layer. (B) Average of 20 randomly-acquired Raman spectra of a graphene sample before the chemical functionalization (pSLG, in black) and after (fSLG, in red) exhibiting the typical bands of CVD graphene in both conditions (ΔI D /I G of about 0.29). It is worth noting that peaks’ shape was impacted by the sporadic presence of double layer nucleation sites. (C) Schematic of the diazonium coupling onto pSLG by using 4-(carboxymethyl)benzene diazonium tetrafluoroborate to obtain fSLG. (D) Box plot of the I D /I G ratio for pSLG and fSLG. The plot showed a significant change after functionalization reaction, which confirms the covalent modification of graphene. (E) AFM topographic images of glass (left), pSLG (middle), and fSLG (right) surfaces before cell plating. Below, the representative topographic profiles relative to the highlighted lines in the images are shown.

Article Snippet: A 700 nm thick sacrificial layer of polymethyl methacrylate (PMMA) was spin-coated above the graphene (7% 950k MW dissolved in anisole, Micro Resist Technology GmbH, DE).

Techniques: Dissolution, Modification