A method to fabricate an optical scattering probe and the method includes the steps of a) depositing an conductive layer on a substrate followed by depositing a noble metal layer on top of the conductive layer and then an aluminum layer on top the noble metal layer; b) anodizing the aluminum layer to form a porous aluminum oxide layer having a plurality of pores; and c) etching the plurality of pores through the aluminum oxide layer and the noble metal layer for forming a nano-hole array. In a preferred embodiment, the step of etching the plurality of pores through the aluminum oxide layer and the noble metal layer further comprising a step of widening the pores followed by removing the aluminum oxide layer for forming a plurality of noble metal column on top of the conductive layer.