Detecting the chemoselective ligation of peptides to silicon with the use of cobalt-carbonyl labels

While fluorescent-based methods are generally used to detect the immobilization and the interactions of biomolecules to solid supports, recent studies have shown their limitations in the case of silicon surfaces. As an alternative, we investigated the synthesis of peptides labeled with a metal transition complex and their subsequent immobilization to the silicon surfaces. The feasibility of using such probes has been explored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). By starting with hydrogen-terminated or oxidized silicon surfaces, we functionalized those surfaces with semicarbazide groups and showed the site-specific linkage of glyoxylyl peptides labeled with a Co2(CO)6 moiety.