Nitric oxide enhances the capacitance of self-assembled, supported bilayer lipid membranes

Abstract

The effect of nitric oxide (NO) at biologically relevant concentrations on the electrochemical features of the membrane was investigated by cyclic voltammetry (CV) at self-assembled, stainless steel supported lipid bilayer membranes (s-BLMs) using a three-electrode system. The results showed that the membrane capacitance ( C m) of s-BLMs was dramatically enhanced by the presence of increasing NO concentration from 0 to 70 μM. For comparison, fullerene C 60 doped s-BLMs (C 60@s-BLMs) was also studied. The C m of C 60@s-BLMs increased with NO concentration from 0 to 16 μM and gradually reached a plateau value when NO concentration was over 16 μM. We concluded that (i) NO accumulated inside lipid bilayer increases the C m of s-BLMs, and (ii) C 60 inside s-BLMs changes the dielectric constant of lipid bilayer, thus reducing the effect of NO on the C m of C 60@s-BLMs. This novel self-assembled lipid modified probe provides a simple yet interesting model to study the effect of NO on the electrical conductance of the membrane.