Biomimetic Phospholipid Membrane Organization on Graphene and Graphene Oxide Surfaces: A Molecular Dynamics Simulation Study

Abstract

Supported phospholipid membrane patches stabilized on graphene surfaces have shown potential in sensor device functionalization, including biosensors and biocatalysis. Lipid dip-pen nanolithography (L-DPN) is a method useful in generating supported membrane structures that maintain lipid functionality, such as exhibiting specific interactions with protein molecules. Here, we have integrated L-DPN, atomic force microscopy, and coarse-grained molecular dynamics simulation methods to characterize the molecular properties of supported lipid membranes (SLMs) on graphene and graphene oxide supports. We observed substantial differences in the topologies of the stabilized lipid structures depending on the nature of the surface (polar graphene oxide vs nonpolar graphene). Furthermore, the addition of water to SLM systems resulted in large-scale reorganization of the lipid structures, with measurable effects on lipid lateral mobility within the supported membranes. We also observed reduced lipid ordering within the supported structures relative to free-standing lipid bilayers, attributed to the strong hydrophobic interactions between the lipids and support. Together, our results provide insight into the molecular effects of graphene and graphene oxide surfaces on lipid bilayer membranes. This will be important in the design of these surfaces for applications such as biosensor devices.

Interaction modes between nanosized graphene flakes and liposomes: Adsorption, insertion and membrane fusion

“…Molecular dynamics (MD) simulations provide an excellent approach to unveil the ultimate molecular mechanisms regulating the behavior of interacting systems and they have been successfully used to obtain direct insights into many lipid membrane processes. Since the completion of the different graphene/membrane interaction modes may require hundreds of nanoseconds or up to several microseconds, coarse-grained (CG) MD simulations have been used to capture them, still preserving the molecular nature of the simulated species [18][19][20][21]. The simulations reveal that despite the intrinsic energy barrier against bilayer penetration, small graphene flakes may spontaneously enter a lipid bilayer by locally piercing it by a corner of the graphene sheet [18,19].…”

Development of Dip‐Pen Nanolithography (DPN) and Its Derivatives

“…One well‐known example of this kind is phospholipids . In the DPN of phospholipids, also known as lipid‐DPN (L‐DPN), amphiphilic lipid molecules are written and self‐assemble into ordered stacks of membranes . By virtue of the layered self‐assembly of the molecules which also includes surface diffusion in the process, yet a more liquid ink like bulk transition of material at the same time, this ink combines aspects of both ink regimes discussed above …”

Potentiometric Biosensing Applications of Graphene Electrodes with Stabilized Polymer Lipid Membranes

“…Supported phospholipid membrane patches were stabilized on graphene surfaces, exhibiting potential for biosensor device construction [20]. Lipid dip-pen nanolithography was applied.…”

“…Lipid dip-pen nanolithography was applied. Atomic force microscopy and coarse-grained molecular dynamics simulation methods were used to characterize the molecular properties of supported lipid membranes materials such as graphene and graphene oxide [20]. Large differences in the topologies of the film structures were discovered, which depended on the nature of the surface.…”