The effect of the trehalose on the physical properties of the fluidic lipid bilayer was studied using surface plasmon resonance (SPR) and cyclic voltammetry (CV). The bilayer was fabricated by tethering 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol on a gold surface to form a monolayer and then using liposomes to adsorb an upper layer on the tethered monolayer. The liposomes were prepared with a desired ratio (mol/mol) of trehalose to lipid, before the adsorption was performed. The formation of the adsorbed layer was monitored with SPR, and the SPR responses were converted to the surface density of the layer. In addition, the CV measurement was conducted to acquire the current-potential responses to evaluate the charge permeability of the layer. The surface density was gradually increased with the trehalose ratio up to 0.5, while the charge permeability was decreased. From these changes, the trehalose appears to be related to the curvature generation induced by the trehalose, which is consistent with the previous simulation results. In the identical measurements at glucose, little change in the properties was observed with even up to 2:1 ratio of glucose:lipid. These results seem attributed to the osmotic and volumetric effect on the headgroup packing disruption. The present study may provide a unique platform to control biological functions related to cellular processes.
Keywords: CV; SPR; Trehalose.