A useful method of modifying the surface of diamond powder with sulfur-containing functionalities was developed by the photolysis of elemental sulfur. The introduction of sulfur-containing functional groups on the diamond surfaces was confirmed by X-ray photoelectron spectroscopy (XPS), diffuse reflectance Fourier transform infrared spectroscopy (DRIFT) and mass spectroscopy analyses. The sulfur-modified diamond powder attached to gold surfaces through sulfur-containing linkages. In brief, the exposure of the modified diamond powder to a gold colloid resulted in gold nanoparticles being attached to the diamond powder. The treatment of the modified diamond powder with thin gold film on a Si substrate resulted in the alignment of surface-attached diamond powder through sulfur linkages formed by self-assembly.