| Abstract: |
The self-assembled monolayers (SAMs) of the ?-methyl oligo(ethylene oxide) disulfide [S(CH2CH2O)6CH3]2, [S(EO)6]2 {OEO disulfide}, on Au from 95 % ethanol and from water are described. Spectroscopic ellipsometry and reflection-absorption infrared spectroscopy data indicate the [S(EO)6]2 films are similar to the disordered films of HS(CH2CH2O)6CH3, (EO)6, and HS(CH2)3O(CH2CH2O)5CH3, C3EO5, at their protein adsorption minima. However, unlike the (EO)6 and C3EO5 thiols, the [S(EO)6]2 films are self-limiting in their surface packing density and sustain film thickness of 1.0 nm to 1.3 nm, corresponding to 50 % to 65 % coverage, over extended periods of time. As a result, OEO disulfides offer an attractive motif for the generation of thin, protein rejecting surfaces. |
