Limits...
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

Comparison of thermal stability for the substrates with (a) and without (b) graphene protection under continuous laser excitation. An obvious photocarbonization effect was observed in the substrate without graphene protection after 3 s of excitation. Laser power density is 2 × 108 mW/cm2. Each spectrum has an acquisition time of 1 s.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4663485&req=5

f6: Comparison of thermal stability for the substrates with (a) and without (b) graphene protection under continuous laser excitation. An obvious photocarbonization effect was observed in the substrate without graphene protection after 3 s of excitation. Laser power density is 2 × 108 mW/cm2. Each spectrum has an acquisition time of 1 s.

Mentions: As an adverse side-effect of the enhanced LSPR adsorption, photocarbonization and photobleaching are inherent and frequently encountered problems in the SERS measurements37. In this work, we observed the graphene coating could alleviate these photo-induced damage to both the substrate and the analyte. As demonstrated by following test, we repeatedly measured the SERS spectra at a fixed point on the substrate under continuous laser excitation. Figure 6a shows the spectra during a period of 20 s illumination (laser intensity is about 1.5 × 108 mW/cm2). The CV signal on the graphene-shielded substrates remained stable. Under same conditions, for the uncovered substrate, an obvious photocarbonization occured only after 3 s of illmunination (Fig. 6b). Even illuminated with lower laser intensities (7.5 × 107, 3.8 × 107 mW/cm2), the photocarbonization still happened after 5 s and 10 s, respectively (data not shown). This may attribute to the extremely high thermal conductivity38 of the graphene coating, due to its long phonon mean free paths. Thus, this feature may also help to improve the reproducibility of SERS measurement by reducing the signal fluctuation caused by photo-induced damage.


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)

Comparison of thermal stability for the substrates with (a) and without (b) graphene protection under continuous laser excitation. An obvious photocarbonization effect was observed in the substrate without graphene protection after 3 s of excitation. Laser power density is 2 × 108 mW/cm2. Each spectrum has an acquisition time of 1 s.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: Comparison of thermal stability for the substrates with (a) and without (b) graphene protection under continuous laser excitation. An obvious photocarbonization effect was observed in the substrate without graphene protection after 3 s of excitation. Laser power density is 2 × 108 mW/cm2. Each spectrum has an acquisition time of 1 s.
Mentions: As an adverse side-effect of the enhanced LSPR adsorption, photocarbonization and photobleaching are inherent and frequently encountered problems in the SERS measurements37. In this work, we observed the graphene coating could alleviate these photo-induced damage to both the substrate and the analyte. As demonstrated by following test, we repeatedly measured the SERS spectra at a fixed point on the substrate under continuous laser excitation. Figure 6a shows the spectra during a period of 20 s illumination (laser intensity is about 1.5 × 108 mW/cm2). The CV signal on the graphene-shielded substrates remained stable. Under same conditions, for the uncovered substrate, an obvious photocarbonization occured only after 3 s of illmunination (Fig. 6b). Even illuminated with lower laser intensities (7.5 × 107, 3.8 × 107 mW/cm2), the photocarbonization still happened after 5 s and 10 s, respectively (data not shown). This may attribute to the extremely high thermal conductivity38 of the graphene coating, due to its long phonon mean free paths. Thus, this feature may also help to improve the reproducibility of SERS measurement by reducing the signal fluctuation caused by photo-induced damage.

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