Y.-J. Oh and K.-H. Jeong report the enhancement of surface-enhanced Raman scattering (SERS) using glass nanopillars surrounded by nanogap-rich silver nanoislands at wafer level. On page 2234, they explain how high-density hot spots are generated by increasing the number of nanogap-rich nanoislands within a detection volume. The SERS substrate shows high enhancement factor with excellent signal uniformity. This novel substrate enables the label-free detection of aqueous DNA base molecules at nanomolar level.