| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 866296 | Biosensors and Bioelectronics | 2015 | 10 Pages |
•Well-ordered Au or Ag nanoclusters (NCs) on Au nanorods (NRs) are fabricated by combining focused ion beam (FIB) and electron beam deposition methods.•The diameter and the formation of NCs on NRs affect SERS effect, which can detect a single molecule of crystal violet.•The small nanogaps between 4-aminobenzenethiol-coated nanoparticles and intra-NCs allowed increase the local field effect.•NCsfibAu_NR was competent to detect matrix-metalloproteinase-9-digested collagen-I fibers of various concentrations.
Well-ordered Au-nanorod arrays were fabricated using the focused ion beam method (denoted as fibAu_NR). Au or Ag nanoclusters (NCs) of various sizes and dimensions were then deposited on the fibAu_NR arrays using electron beam deposition to improve the surface-enhanced Raman scattering (SERS) effect, which was verified using a low concentration of crystal violet (10–5 M) as the probe molecule. An enhancement factor of 6.92×108 was obtained for NCsfibAu_NR, which is attributed to the combination of intra-NC and NR localized surface plasmon resonance. When 4-aminobenzenethiol (4-ABT)-coated Au or Ag nanoparticles (NPs) were attached to NCsfibAu_NR, the small gaps between 4-ABT-coated NPs and intra-NCs allowed detection at the single-molecule level. Hotspots formed at the interfaces of NCs/NRs and NPs/NCs at a high density, producing a strong local electromagnetic effect. Raman spectra from as-prepared type I collagen (Col-I) and Ag-NP-coated Col-I fibers on NCsfibAu_NR were compared to determine the quantity of amino acids in their triple helix structure. Various concentrations of matrix-metalloproteinase-9-digested Col-I fibers on NCsfibAu_NR were qualitatively examined at a Raman laser wavelength of 785 nm to determine the changes of amino acids in the Col-I fiber structure. The results can be used to monitor the growth of healing Col-I fibers in a micro-environment.
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