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Nanoimprint lithography of Al nanovoids for deep-UV SERS.

Ding T, Sigle DO, Herrmann LO, Wolverson D, Baumberg JJ - ACS Appl Mater Interfaces (2014)

Bottom Line: Deep-ultraviolet surface-enhanced Raman scattering (UV-SERS) is a promising technique for bioimaging and detection because many biological molecules possess UV absorption lines leading to strongly resonant Raman scattering.Here, Al nanovoid substrates are developed by combining nanoimprint lithography of etched polymer/silica opal films with electron beam evaporation, to give a high-performance sensing platform for UV-SERS.Enhancement by more than 3 orders of magnitude in the UV-SERS performance was obtained from the DNA base adenine, matching well the UV plasmonic optical signatures and simulations, demonstrating its suitability for biodetection.

View Article: PubMed Central - PubMed

Affiliation: Nanophotonics Centre, Cavendish Laboratory, University of Cambridge , Cambridge CB3 0HE, United Kingdom.

ABSTRACT
Deep-ultraviolet surface-enhanced Raman scattering (UV-SERS) is a promising technique for bioimaging and detection because many biological molecules possess UV absorption lines leading to strongly resonant Raman scattering. Here, Al nanovoid substrates are developed by combining nanoimprint lithography of etched polymer/silica opal films with electron beam evaporation, to give a high-performance sensing platform for UV-SERS. Enhancement by more than 3 orders of magnitude in the UV-SERS performance was obtained from the DNA base adenine, matching well the UV plasmonic optical signatures and simulations, demonstrating its suitability for biodetection.

No MeSH data available.


Related in: MedlinePlus

(a) SEM and (b) AFM imagesof Al nanovoids. Scale bars are 1 and 2 μm, respectively. Theinset in a shows the cm-sized imprinted nanovoid, scale bar is 5 mm.Inset in b is the fast Fourier transfer (FFT) of the AFM image, showingwell-defined order. (c) Surface height profile of the nanovoids, insetis zoomed view. (d) Dark field scattering spectra of the Al nanovoids,showing experimental data (red line), simulation (blue dashed), andcontrol for flat Al films (black solid line). Insets are the electricfield profile of the Al nanovoids at the spectral peak.
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fig2: (a) SEM and (b) AFM imagesof Al nanovoids. Scale bars are 1 and 2 μm, respectively. Theinset in a shows the cm-sized imprinted nanovoid, scale bar is 5 mm.Inset in b is the fast Fourier transfer (FFT) of the AFM image, showingwell-defined order. (c) Surface height profile of the nanovoids, insetis zoomed view. (d) Dark field scattering spectra of the Al nanovoids,showing experimental data (red line), simulation (blue dashed), andcontrol for flat Al films (black solid line). Insets are the electricfield profile of the Al nanovoids at the spectral peak.

Mentions: Regular arrays of Al nanovoids are generated afterthe imprinting and metal coating process (Figure 2a). The AFM image in Figure 2b confirmsthe ordered arrays of nanovoids with honeycomb-like arrangement, whichis the negative print of the silica array on the POF stamp. The heightprofile in Figure 2c shows a 20 nm maximumdepth across the 180 nm diameter of the nanovoids, which almost exactlymatches (see the Supporting Information, Figure S3) the feature sizes of the original POF stamp (diameter200 nm, 15 nm height in crest). Although the short-range order isvery good with domain sizes of several microns, the long rang orderis interspersed with occasional defects. These defects observablein the AFM image (Figure 2b) are of height∼30 nm and occur on only <8% of sites introduced duringthe imprinting process. They originate both from flakes of PMMA/PEAdetaching after etching the silica nanospheres in the POF stamps,and from defects of the stamps.


Nanoimprint lithography of Al nanovoids for deep-UV SERS.

Ding T, Sigle DO, Herrmann LO, Wolverson D, Baumberg JJ - ACS Appl Mater Interfaces (2014)

(a) SEM and (b) AFM imagesof Al nanovoids. Scale bars are 1 and 2 μm, respectively. Theinset in a shows the cm-sized imprinted nanovoid, scale bar is 5 mm.Inset in b is the fast Fourier transfer (FFT) of the AFM image, showingwell-defined order. (c) Surface height profile of the nanovoids, insetis zoomed view. (d) Dark field scattering spectra of the Al nanovoids,showing experimental data (red line), simulation (blue dashed), andcontrol for flat Al films (black solid line). Insets are the electricfield profile of the Al nanovoids at the spectral peak.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230348&req=5

fig2: (a) SEM and (b) AFM imagesof Al nanovoids. Scale bars are 1 and 2 μm, respectively. Theinset in a shows the cm-sized imprinted nanovoid, scale bar is 5 mm.Inset in b is the fast Fourier transfer (FFT) of the AFM image, showingwell-defined order. (c) Surface height profile of the nanovoids, insetis zoomed view. (d) Dark field scattering spectra of the Al nanovoids,showing experimental data (red line), simulation (blue dashed), andcontrol for flat Al films (black solid line). Insets are the electricfield profile of the Al nanovoids at the spectral peak.
Mentions: Regular arrays of Al nanovoids are generated afterthe imprinting and metal coating process (Figure 2a). The AFM image in Figure 2b confirmsthe ordered arrays of nanovoids with honeycomb-like arrangement, whichis the negative print of the silica array on the POF stamp. The heightprofile in Figure 2c shows a 20 nm maximumdepth across the 180 nm diameter of the nanovoids, which almost exactlymatches (see the Supporting Information, Figure S3) the feature sizes of the original POF stamp (diameter200 nm, 15 nm height in crest). Although the short-range order isvery good with domain sizes of several microns, the long rang orderis interspersed with occasional defects. These defects observablein the AFM image (Figure 2b) are of height∼30 nm and occur on only <8% of sites introduced duringthe imprinting process. They originate both from flakes of PMMA/PEAdetaching after etching the silica nanospheres in the POF stamps,and from defects of the stamps.

Bottom Line: Deep-ultraviolet surface-enhanced Raman scattering (UV-SERS) is a promising technique for bioimaging and detection because many biological molecules possess UV absorption lines leading to strongly resonant Raman scattering.Here, Al nanovoid substrates are developed by combining nanoimprint lithography of etched polymer/silica opal films with electron beam evaporation, to give a high-performance sensing platform for UV-SERS.Enhancement by more than 3 orders of magnitude in the UV-SERS performance was obtained from the DNA base adenine, matching well the UV plasmonic optical signatures and simulations, demonstrating its suitability for biodetection.

View Article: PubMed Central - PubMed

Affiliation: Nanophotonics Centre, Cavendish Laboratory, University of Cambridge , Cambridge CB3 0HE, United Kingdom.

ABSTRACT
Deep-ultraviolet surface-enhanced Raman scattering (UV-SERS) is a promising technique for bioimaging and detection because many biological molecules possess UV absorption lines leading to strongly resonant Raman scattering. Here, Al nanovoid substrates are developed by combining nanoimprint lithography of etched polymer/silica opal films with electron beam evaporation, to give a high-performance sensing platform for UV-SERS. Enhancement by more than 3 orders of magnitude in the UV-SERS performance was obtained from the DNA base adenine, matching well the UV plasmonic optical signatures and simulations, demonstrating its suitability for biodetection.

No MeSH data available.


Related in: MedlinePlus