Influence of constitution of hybrid ferrocenyl alkanethiols self-assembled monolayers to interfacial characteristics on gold surface

摘要

The interfacial characteristics of self-assembled monolayer (SAM), that are applied in miniaturized sensor design, were strongly influenced by the SAM constitution. The electrochemical and interfacial characteristics of hybrid SAMs that constituted with ferrocenyl octanethiol (FcC_8SH) and unsubstituted octanethiol (C_8) or 2-mercaptopyrimidine (2-MPD) were investigated in this study. The peaks of anodic oxidation were observed at around 0.49 V (vs. Ag/AgCl) in the FcC_8SH/C_8 hybrid SAM. However, the oxidation potentials descended from 0.420.38 V as the molar fraction of FcC_8SH was decreased from 0.80.2 in the FcC _8SH/2-MPD hybrid SAM. On the other hand, the interfacial hydrophilicity of FcC_8SH/2-MPD hybrid SAM was measured to be higher than the FcC_8SH/C_8 hybrid SAM due to the random arrangement of SAM caused by the shape of 2-MPD. Then, the surface roughness of hybrid SAM and chain length of ferrocenyl alkanethiols were all considered to be the parameters of interfacial characteristics. In summary, doping of 2-MPD in SAMs might reduce the rigidity of ferrocenyl alkanethiol SAMs and increase the interfacial hydrophilicity. This result will be useful in the development of the low power consumption portable bioanalytical system. And a miniaturized bioanalytical system based on ferrocenyl SAMs would be developed in the future.