Collagen is the principal tensile element of the extra-cellular matrix in animals and is the basic scaffold for cells and tissues. Abnormalities in its structure are known to result in a number of debilitating human diseases. Collagen mimetic peptides (CMPs) with repeat unit of (Pro-Hyp-Gly) are capable of forming right-handed triple-helical structures similar to that of the collagen triple helices. Recently, our group has shown that CMPs exhibit specific binding affinity to natural collagen under controlled thermal conditions. Using solid phase peptide synthesis, we have prepared a CMP cysteine derivative that was used to modify gold nanoparticles. Transmission electron microscopy (TEM) shows that the Cys-CMP functionalized gold nanoparticles have affinity to collagen fibers. We are investigating the interactions between Cys-CMP functionalized gold nanoparticles and collagen fibers. The Cys-CMP conjugated nanoparticles can potentially be used as a tool to visualize and understand unstable domains of collagen fibers which are related to a number of pathological conditions of extra cellular matrices.