In a method of fabricating an apparatus for use in a sensing application, a plurality of nano-fingers are formed on a substrate and a Raman-active material nano-particle is formed on respective tips of the nano-fingers. In addition, the Raman-active material nano-particles on the tips of adjacent ones of the nano-fingers are caused to come into contact with the Raman-active material nano-particle on the tip of at least another one of the plurality of nano-fingers to form respective clusters and the clusters of Raman-active material nano-particles are transferred to a component layer from the plurality of nano-fingers while maintaining a spatial relationship between the contacting Raman-active material nano-particles.