The direct sulfurization of diamond-like carbon (DLC) film surfaces by a photochemical reaction with elemental sulfur was realized. The surface modification of DLC films with thiol functional group was confirmed by X-ray photoelectron spectroscopy (XPS) with the maintenance of DLC bulk structure characterized by Raman spectroscopy. The exposure of gold nanoparticles to the thiol-modified DLC films led to the attachment of gold nanoparticles onto DLC films by self-assembly, confirming by XPS and scanning electron microscopy (SEM). The gold-modified DLC film was also observed to act as a substrate for DNA immobilization by hybridization. The gold nanoparticles on the DLC surfaces were embedded by the deposition of an additional DLC layer onto the gold-modified DLC film to form a sandwich structure, and the resulting structure acted as a substrate exhibiting surface-enhanced Raman scattering. (C) 2014 Elsevier B.V. All rights reserved.