Figure 4.
Fresnel-normalized x-ray reflectivity data (circles) obtained via the interferometric approach for (i) a Si-Ni-Si multilayer reference structure with SAM and linker and (ii) the overlying SAP2C monolayer covalently attached to the surface of the Si-Ni-Si multilayer structure; (a) shows these data on a linear ordinate scale while (b) utilizes a corresponding log scale. (c) Corresponding electron density profiles derived for the multilayer substrate-peptide overlayer system. (d) Difference between the electron density profile for the Si-Ni-Si reference structure itself and with the SAP2C monolayer overlying the Si-Ni-Si structure [i.e., profile for SAP2C on Si-Ni-Si] minus that for [Si-Ni-Si].