Periodic metallic nanopyramid arrays as Surface Enhanced Raman Scattering (SERS) substrates

ANYL 460

Nicholas Linn, nclinn@ufl.edu, Chih-hung Sun, csun@che.ufl.edu, and Peng Jiang, pjiang@che.ufl.edu. Department of Chemical Engineering, University of Florida, Gainesville, FL 32611
We present a non-lithographic technique for creating wafer-scale metallic nanopyramid arrays using colloidal self-assembly and templated synthesis. In this method, silica nanoparticles created by the Stober process are suspended in an acrylate momomer and spin coated on a (100) silicon wafer, yielding a non-close-packed colloidal monolayer. Employing reactive ion etching, Cr sputtering, and finally an anisotropic wet etching step, the nanosphere array is transferred into the silicon substrate as a nanopyramid hole array. Subsequent replication of the array into a noble metal (Au or Ag) results in a periodic nanopyramid array with sub-20-nm sharp tips, which can significantly enhance local electromagnetic field at the nanotips for surface enhanced Raman scattering (SERS) active substrate. These templated nanotip arrays are of great technological applications in ultrasensitive biomolecular detection.