Investigation of two-component mixed self-assembled monolayers on gold

Two-component mixed self-assembled monolayers (SAMs) composed of 2-mercapto -5-methyl-1,3,4-oxadiazole (MMO) and 1-dodecanethiol (C12SH) in various mol ar percentages were prepared on gold surfaces by self-assembly. X-ray photo electron spectroscopy (XPS) and wettability results gave evidence that the coverage of MMO was controlled by the composition of MMO in the assembling solution. The monolayer coverage and apparent rate constant of the redox ac tive probes in solution of different molar ratios of mixed SAMs could be ca lculated using impedance measurements. The cyclic voltammetry reveals that the probes are selectively passed through the mixed SAMs depending upon the ir properties.