Intense SERS Effect From a Single Metallized Silicon Nanowire

Metallized silicon (Si) nanowires are created by just by dipping the nanowires into an aqueous deposition solution for several minutes. Upon dipping into solution, metal ions were reduced and deposited on the top of the Si nanowire. Surface silicon oxide was simultaneously dissolved and removed by hydrogen fluoride (HF), so that the deposition reaction was sustainable and controllable. The deposited silver (Ag) nanoparticles (NPs) uniformly covered the silicon nanowires. Also Cu, Pd, Co, Au, and Pt were deposited to metallize the silicon nanowires in a similar manner. Applications of the new nano-composite materials were explored. When the Ag coated silicon nanowire was tested as a Surface-Enhanced Raman Scattering (SERS) substrate, an extremely strong signal was observed. The significantly enhanced SERS effect appears to be associated with the close packing of the neighboring NPs that self-assemble along the highly curved nanowire [1].

[1] C Fang, A Agarwal, E Widjaja, M Garland, SM Wong, L Linn, M K Nizamudin , S M Salim, and N Balasubramanian Chem. Mater. 2009, 21, 3542–3548