Abstract
An ideal surface-enhanced Raman scattering (SERS) nanostructure for sensing and imaging applications should induce a high signal enhancement, generate a reproducible and uniform response, and should be easy to synthesize. Many SERS-active nanostructures have been investigated, but they suffer from poor reproducibility of the SERS-active sites, and the wide distribution of their enhancement factor values results in an unquantifiable SERS signal. Here, we show that DNA on gold nanoparticles facilitates the formation of well-defined gold nanobridged nanogap particles (Au-NNP) that generate a highly stable and reproducible SERS signal. The uniform and hollow gap (∼1 nm) between the gold core and gold shell can be precisely loaded with a quantifiable amount of Raman dyes. SERS signals generated by Au-NNPs showed a linear dependence on probe concentration (R2>0.98) and were sensitive down to 10 fM concentrations. Single-particle nano-Raman mapping analysis revealed that >90% of Au-NNPs had enhancement factors greater than 1.0 × 10 8, which is sufficient for single-molecule detection, and the values were narrowly distributed between 1.0 × 108 and 5.0 × 108.
Original language | English |
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Pages (from-to) | 452-460 |
Number of pages | 9 |
Journal | Nature Nanotechnology |
Volume | 6 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2011 Jul |
Externally published | Yes |
ASJC Scopus subject areas
- Bioengineering
- Atomic and Molecular Physics, and Optics
- Biomedical Engineering
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering