The surface enhanced Raman spectroscopy (SERS) is one of the most sensitive tools for trace analysis and the fabrication of effective and robust SERS substrates is the subject of intensive research in view of their possible applications. In this Letter, the SERS activity of an ordered structure of inverted pyramids (Klarite, Ltd) was examined by using nitro-based explosives, as Raman probe molecules. Enhancement factors up to 10(6) and detection limits of tens of pg were measured with an excellent run to run reproducibility. These findings provide new opportunities for the utilization of SERS for analytical detection at trace level. (C) 2013 Elsevier B.V. All rights reserved.