Speaker
Description
Biosensing using graphene field-effect transistors (GFETs) is an emerging research area in which device reliability and performance critically depend on the functionalization of the graphene surface. Non-covalent grafting of molecular receptors via π–π stacking is widely employed to induce chemical specificity while preserving graphene’s electronic properties. However, the microscopic mechanisms governing these interactions and their impact on GFET response remain insufficiently understood.
In this work, we investigate the non-covalent functionalization of graphene using transmission infrared spectroscopy combined with electrical transport measurements through GFET transfer curves. Graphene transferred onto MgF₂ substrates is functionalized with 1-pyrenecarboxylic acid (1-PCA), a molecule composed of a pyrene base and a carboxylic acid head. Infrared spectra are acquired for pristine graphene, 1-PCA molecules,their combination in a single layer of molecules adsorbed on graphene, and multiple stacked layers, allowing us to track vibrational mode shifts associated with π–π interactions and intermolecular coupling. Our preliminary results show modifications of characteristic vibrational modes upon adsorption and stacking, indicating changes in both the molecule-molecule and the graphene–molecule interaction strength. In parallel, gold electrodes deposited on the substrate enable liquid-gated GFET measurements. Transfer curves are recorded after successive 1-PCA incubation steps, revealing shifts in charge neutrality point and carrier transport properties.
The combined spectroscopic and electrical analysis offers insights in how molecular organization and stacking influence GFET response. These results contribute to a deeper understanding of graphene surface functionalization and offer guidelines for optimizing non-covalent grafting strategies in GFET-based biosensors.
| Keyword-1 | Graphene |
|---|---|
| Keyword-2 | Infrared Spectroscopy |
| Keyword-3 | GFET |