This work presents a convenient method to fabricate large-area 'scrobiculate sub-10 nm Ag nanocavity arrays (NCA) through a facile replication and deposition process. Periodical cone-shaped NCA were constructed on the composite multi-layered noble metal film with cavity diameters abridged to the sub-10 nm scale. The resultant Ag NCA exhibited excellent SERS characteristic for Rhodamine 6G (R6G) and achieved a high enhancement factor of 3 x 10(9). The enhancement was found to be quantitatively related to the concentration of the R6G probe solutions. The enhancement characteristic was testified via a Raman mapping across a 50 x 50 mu m area on the substrate surface and achieved high homogeneity within the territory. For the SERS determination of Polychlorinated Biphenyls (PCBs), the surface of the NCA was modified with thiolated beta-Cyclodextrin (HS-beta-CD) and was thus functionalized as an incubation host for the PCBs molecules. Results suggest that the as-fabricated substrates show great potential in the SERS determination of the PCBs. (C) 2016 Elsevier B.V. All rights reserved.