Controlling fluorescence quenching efficiency by graphene oxide in supported lipid bilayers using SiO2 layer fabricated by atomic layer deposition


 The SiO2 layer fabricated by the atomic layer deposition (ALD) method was applied to control the efficiency of the fluorescence quenching by graphene oxide (GO) in supported lipid bilayers (SLBs). SLB was formed by the vesicle fusion method on the ALD-SiO2 layer on GO deposited on thermally oxidized SiO2/Si substrates. Wide-field fluorescence observation of SLB on ALD-SiO2 layers with various thickness showed that the ALD-SiO2 layer varied the efficiency of fluorescence quenching with reasonable distance dependence expected from the equation of fluorescence resonance energy transfer. Fluorescence single molecular observation of dye-labeled lipids was achieved in SLB existing in the effective range of the quenching by GO. Quenching experiment using Co2+ that selectively quenches the fluorescence from the upper leaflet of SLB revealed the difference in the fluorescence intensity between the upper and lower leaflets of SLB due to their distance from GO.