Self-assembled monolayers (SAMs) have become an essential technique for biochemical modification of a biomaterial surface using specific peptides. Previous studies reported effects of their terminal functionalities including organic molecules on apatite formation in a simulated body fluid. Biological responses are influenced by the surface chemical characteristics of SAMs as well. This study investigated the adsorption behavior of alkanethiol and two alkanesilanes on modified titanium surfaces using an electrochemical quartz crystal nanobalance (EQCN). The formation of SAMs on three working electrode surfaces: Au coated Ti, commercialized pure Ti (c.pTi) and TiO2 were also examined. The resolution limit obtained for the constructed EQCN was about 0.1 ng. The mass change ratio on the surfaces versus immersion time was investigated using EQCN. The quantity of Thiol-I SAM adsorbed on c.pTi is about 67% compared with the quantity formed on Au coated titanium substrate. Contrarily, there was no SAM formation on the TiO2 surface with a thick titanium oxide layer obtained by the electrochemical oxidation method. The SAM amounts (for organosilanes) adsorbed on TiO2 surfaces of Silane-I[ (CH3O)3Si(SH2)3NHCH2CH2NH2)] and Silane-II[H2N(CHS)3Si(OCH3)3] were approximately 19% and 14% more than that of c.pTi. The results obtained in this study show that by altering titanium surface chemistry and introducing functional groups, titanium surfaces may be modified into functional bioactive surfaces and can be used in the same way as the Au substrate.

Keywords: Titanium, Surface Modification, Alkanethiol, Organosilane, EQCN