Large-scale growth of sharp gold nano-cones for single-molecule SERS detection
We report a novel approach for large-scale gold nano-cone growth by utilizing the open nanopore channels of nanoporous gold films as both the template for nano-cone growth and the delivery channel of the reduction gas through the nano-pipes. Quasi-periodic nano-cone arrays uniformly sprout on the centimeter-sized free-standing nanoporous gold films. The sharp nano-cones give rise to ultrahigh surface enhanced Raman scattering for single molecule detection from the focused electromagnetic fields at the cone apexes. The large-scale nano-cone decorated nanoporous gold films may serve as high-performance SERS substrates for wide-ranging applications in ultrasensitive instrumentation and molecule diagnostics.