The immobilization method and atomic concentrations of Si 2p, Au 4f, S 2p, C 1s, N 1s, and O 1s of the resulting SA–biotin modified Si surface were determined by XPS. The CD spectrum and confocal microscopy imaging confirmed that step-by-step modification and bioconjugation can be monitored successfully. Such detailed and well-defined step-by-step characterization provides good information about the surface properties of biosensor platforms. In addition, the LSPR sensing ability of the Au Np based platforms was studied by using a model SA–biotin system. |