A novel surface-enhanced Raman spectroscopy (SERS) substrate based on uniform silver nanoparticles/silicon nanoporous pyramid arrays (Ag/PS) is prepared and SERS behaviors to adenosine are discussed and compared. With a low concentration of 10(-7)M, the characteristic Raman bands of adenosine demonstrate the significantly high SERS sensitivity of the prepared Ag/PS substrate. A reasonable linear correlation is obtained between the intensity of SERS signal and the adenosine concentration from 10(-7) to 10(-7)M in log scale. These results imply that the Ag/PS with regular pyramids array might be an effective substrate for performing label-free sensitive SERS detections of biomolecule. (C) 2015 Elsevier B.V. All rights reserved.