Specific Detection of PE-Included Vesicles Using Cyclic Voltammetry

Abstract

The binding between cinnamycin and the phosphatidylethanolamine (PE)-included vesicles was monitored using cyclic voltammetry (CV) measurements and interpreted in terms of the composition of the vesicles and the monolayer binding site. The monolayer was composed of pure 11-mercapto-1-undecanol (MUD) to 90% MUD/10% 16-mercaptohexadecanoic acid (MHA) on a gold surface. Cinnamycin was immobilized on each monolayer. The vesicles, prepared at the desired ratio of the phospholipids, were injected on the cinnamycin-immobilized surface. CV experiments were performed for each step. For the pure-dipalmitoylphosphatidyl-choline (DPPC) vesicles on all of monolayers and the DPPC/dipalmitoylphosphatidyl-ethanolamine (DPPE) vesicles on the pure-MUD monolayer, the electric property of the surface was little changed. However, the vesicles made with 90% DPPC/10% DPPE on the monolayer prepared with 99% MUD/1% MHA to 90% MUD/10% MHA showed a consistent decrease in the CV response. Additionally, in the 95% DPPC/5% DPPE vesicles and the 99.5% MUD/0.5% MHA monolayer, variances in the responses were observed.