Liquid-Gated Graphene Field-Effect Transistors for Biosensing on Lipid Monolayers

This study presents a comprehensive fabrication process for high-quality graphene field-effect transistors (GFETs) and their characterization. It is demonstrated that the suggested cost-efficient method of fabrication utilizing the direct-laser writing (DLW) system is reliable and ensures lower contact resistance between graphene and metal compared to other works. This improvement results in minimal signal loss and distortion, providing significant benefits to the overall performance of the GFETs. The fabricated devices are functionalized with a lipid monolayer containing tris-nitrilotriacetic acid fused to the lipids for the binding of histidine-tagged proteins. Monomeric enhanced green fluorescent protein (GFP) is used as a model protein to explore the current-voltage characteristics response of the liquid-gated GFETs. The results demonstrate that the devices are well suited for the electrical biosensing of proteins in physiological buffer conditions, paving the way for label-free detection of protein-protein interactions at membranes. This study presents a fabrication process for high-quality graphene field-effect transistors. The fabricated devices are functionalized with a lipid monolayer containing tris-nitrilotriacetic acid fused to the lipids to bind histidine-tagged proteins. The results demonstrate that the devices are well suited for the electrical biosensing of proteins in physiological buffer conditions, paving the way for label-free detection at lipid monolayers.image (c) 2023 WILEY-VCH GmbH