An apparatus for performing surface enhanced Raman spectroscopy includes an optical waveguide, a plurality of flexible nano-structures, wherein the plurality of nano-structures have respective free ends positioned within an evanescent field to be generated by light propagated through the optical waveguide, wherein the plurality of nano-structures are movable from a first position and a second position, wherein in the first position, the free ends of the plurality of nano-structures are substantially spaced from each other and in the second position, the free ends of a plurality of the nano-structures are substantially in contact with each other.