Tunable SERS in gold nanorod dimers through strain control on an elastomeric substrate.

In this Letter we provide experimental verification of the interparticle distance dependence of the SERS enhancement factor in 1 μm gold gapped nanorods. Au dimers are fabricated from electrochemically grown heterogeneous Au-Ag-Au nanorods and deposited on a stretchable elastomer film which allows active and reversible tuning of the interparticle gap on the sub-5-nm level. Significantly, this technique allows the distance dependence to be tracked using a single dimer, thereby avoiding enhancement factor reproducibility issues arising from morphological differences in disparate nanoparticle pairs.