Lipid bilayer is a fundamental structure of plasma membranes, and plays important roles for various membrane reactions such as the transport of material, energy, and information. Graphene oxide (GO) is an amphiphilic atomic sheet, and shows a unique fluorescence quenching property. In this study, we formed supported lipid bilayers (SLB) on GO, and investigated the lateral molecular diffusion and fluorescence quenching efficiency with the single particle tracking (SPT) method.<br/>We formed the SLB comprising of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), polyethylene glycol-1,2-disterol-sn-glycero-3-phosphoethanolamine (PEG-DSPE) and 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) by the vesicle fusion method. The GO suspension was prepared by the modified Hummer’s method, and was dropcast on a thermally oxidized SiO2/Si substrate. A carboxyl-coated quantum dot (Qdot) conjugated to the SLB containing DPPTE with a maleimide-hydrazide hetero-cross-linker.<br/>We measured the diffusion coefficient (D) of the conjugated Qdots on SLB on GO by SPT. Fluorescence dyes are not available under the quenching effect of GO, but Qdot was bright enough for SPT measurement on GO. We analyzed the Qdots diffusing the GO and GO-free SiO2 region, and evaluated D in each region. The SLB on GO had ~30 % smaller D than that on the GO-free SiO2 region. The quenching efficiency on GO, which was calculated from the fluorescence intensity of Qdots on GO, indicated the layer numbers of bilayer on GO.

Lateral diffusion and fluorescence quenching in lipid bilayer membranes on graphene oxide

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.