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Compact Shielding of Graphene Monolayer Leads to Extraordinary SERS-Active Substrate with Large-Area Uniformity and Long-Term Stability.

Liu X, Wang J, Wu Y, Fan T, Xu Y, Tang L, Ying Y - Sci Rep (2015)

Bottom Line: Surface-enhanced Raman scattering (SERS) can significantly boost the inherently weak Raman scattering signal and provide detailed structural information and binding nature of the molecules on the surface.Besides, our fabrication strategy were also capable of fabricating the reproducible SERS sensing spots array, which may serve as a promising high-throughput or multi-analyte sensing platform.Taken together, the graphene-shielded SERS substrate holds great promise both in fundamental studies of the SERS effect and many practical fields.

View Article: PubMed Central - PubMed

Affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.

ABSTRACT
Surface-enhanced Raman scattering (SERS) can significantly boost the inherently weak Raman scattering signal and provide detailed structural information and binding nature of the molecules on the surface. Despite the long history of this technology, SERS has yet to become a sophisticated analytical tool in practical applications. A major obstacle is the absence of high-quality and stable SERS-active substrate. In this work, we report a monolayer graphene-shielded periodic metallic nanostructure as large-area uniform and long-term stable SERS substrate. The monolayer graphene acting as a corrosion barrier, not only greatly enhanced stability, but also endowed many new features to the substrate, such as alleviating the photo-induced damages and improving the detection sensitivity for certain analytes that are weakly adsorbed on the conventional metallic substrates. Besides, our fabrication strategy were also capable of fabricating the reproducible SERS sensing spots array, which may serve as a promising high-throughput or multi-analyte sensing platform. Taken together, the graphene-shielded SERS substrate holds great promise both in fundamental studies of the SERS effect and many practical fields.

No MeSH data available.


Related in: MedlinePlus

Raman spectra recorded from graphene-shielded substrates immersed in different concentration of CV (a) and R6G (b) solutions (50× objective, average of 16 spectra with 1s acquisition time).
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f2: Raman spectra recorded from graphene-shielded substrates immersed in different concentration of CV (a) and R6G (b) solutions (50× objective, average of 16 spectra with 1s acquisition time).

Mentions: To evaluate the SERS activity of the graphene-shielded substrates, crystal violet (CV) and rhodamine 6G (R6G) were used to probe the substrate. The corresponding spectra are displayed in Fig. 2a,b. A positive correlation between the band intensities and the concentrations of the dyes was observed. We noticed that certain Raman bands were distantly visible when CV and R6G concentrations were as low as 10−9 M and 2 × 10−10 M, respectively. The enhancement factor (EF) of the substrate was estimated to be ~107, by calculating the ratio of SERS intensity to the corresponding normal Raman intensity. This value is among the highest EFs measured on similar kind of two-dimension immobilized SERS substrate313435. To evaluate the influence of graphene to the SERS signal, we further compared the SERS signals from the graphene-covered and uncovered area. As shown in Figure S6, we found the signals from graphene covered areas displayed relatively higher intensities. Compared with other commonly used gold nanoparticles (60 nm), our substrates usually generated 2 ~ 3 orders of magnitude higher signals (see Figure S7), suggesting the potentiality of our substrate in trace-level organic compounds analysis.


Compact Shielding of Graphene Monolayer Leads to Extraordinary SERS-Active Substrate with Large-Area Uniformity and Long-Term Stability.

Liu X, Wang J, Wu Y, Fan T, Xu Y, Tang L, Ying Y - Sci Rep (2015)

Raman spectra recorded from graphene-shielded substrates immersed in different concentration of CV (a) and R6G (b) solutions (50× objective, average of 16 spectra with 1s acquisition time).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663485&req=5

f2: Raman spectra recorded from graphene-shielded substrates immersed in different concentration of CV (a) and R6G (b) solutions (50× objective, average of 16 spectra with 1s acquisition time).
Mentions: To evaluate the SERS activity of the graphene-shielded substrates, crystal violet (CV) and rhodamine 6G (R6G) were used to probe the substrate. The corresponding spectra are displayed in Fig. 2a,b. A positive correlation between the band intensities and the concentrations of the dyes was observed. We noticed that certain Raman bands were distantly visible when CV and R6G concentrations were as low as 10−9 M and 2 × 10−10 M, respectively. The enhancement factor (EF) of the substrate was estimated to be ~107, by calculating the ratio of SERS intensity to the corresponding normal Raman intensity. This value is among the highest EFs measured on similar kind of two-dimension immobilized SERS substrate313435. To evaluate the influence of graphene to the SERS signal, we further compared the SERS signals from the graphene-covered and uncovered area. As shown in Figure S6, we found the signals from graphene covered areas displayed relatively higher intensities. Compared with other commonly used gold nanoparticles (60 nm), our substrates usually generated 2 ~ 3 orders of magnitude higher signals (see Figure S7), suggesting the potentiality of our substrate in trace-level organic compounds analysis.

Bottom Line: Surface-enhanced Raman scattering (SERS) can significantly boost the inherently weak Raman scattering signal and provide detailed structural information and binding nature of the molecules on the surface.Besides, our fabrication strategy were also capable of fabricating the reproducible SERS sensing spots array, which may serve as a promising high-throughput or multi-analyte sensing platform.Taken together, the graphene-shielded SERS substrate holds great promise both in fundamental studies of the SERS effect and many practical fields.

View Article: PubMed Central - PubMed

Affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.

ABSTRACT
Surface-enhanced Raman scattering (SERS) can significantly boost the inherently weak Raman scattering signal and provide detailed structural information and binding nature of the molecules on the surface. Despite the long history of this technology, SERS has yet to become a sophisticated analytical tool in practical applications. A major obstacle is the absence of high-quality and stable SERS-active substrate. In this work, we report a monolayer graphene-shielded periodic metallic nanostructure as large-area uniform and long-term stable SERS substrate. The monolayer graphene acting as a corrosion barrier, not only greatly enhanced stability, but also endowed many new features to the substrate, such as alleviating the photo-induced damages and improving the detection sensitivity for certain analytes that are weakly adsorbed on the conventional metallic substrates. Besides, our fabrication strategy were also capable of fabricating the reproducible SERS sensing spots array, which may serve as a promising high-throughput or multi-analyte sensing platform. Taken together, the graphene-shielded SERS substrate holds great promise both in fundamental studies of the SERS effect and many practical fields.

No MeSH data available.


Related in: MedlinePlus