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Nanoparticle properties and synthesis effects on surface-enhanced Raman scattering enhancement factor: an introduction.

Israelsen ND, Hanson C, Vargis E - ScientificWorldJournal (2015)

Bottom Line: However, the inherent insensitivity of the technique makes it difficult to use and statistically complicated.When Raman active molecules are near gold or silver nanoparticles, the Raman intensity is significantly amplified.This phenomenon is referred to as surface-enhanced Raman spectroscopy (SERS).

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322, USA.

ABSTRACT
Raman spectroscopy has enabled researchers to map the specific chemical makeup of surfaces, solutions, and even cells. However, the inherent insensitivity of the technique makes it difficult to use and statistically complicated. When Raman active molecules are near gold or silver nanoparticles, the Raman intensity is significantly amplified. This phenomenon is referred to as surface-enhanced Raman spectroscopy (SERS). The extent of SERS enhancement is due to a variety of factors such as nanoparticle size, shape, material, and configuration. The choice of Raman reporters and protective coatings will also influence SERS enhancement. This review provides an introduction to how these factors influence signal enhancement and how to optimize them during synthesis of SERS nanoparticles.

No MeSH data available.


An illustration of an extrinsic SERS nanoparticle for targeting of a specific antigen.
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fig1: An illustration of an extrinsic SERS nanoparticle for targeting of a specific antigen.

Mentions: Extrinsic SERS is an indirect method of measuring target molecules because the acquired spectrum is of a Raman reporter rather than the target itself. A Raman reporter is a molecule that has inherently strong Raman active modes. An illustration of a nanoparticle used for extrinsic SERS is provided in Figure 1, where a Raman reporter molecule is bound to the metal surface and encased in a protective layer. This protective layer prevents nanoparticle aggregation and reporter leaching by steric hindrance and charge neutralization. The nanoparticle is then functionalized with an antibody or other ligand to target specific molecular sites. Nanoparticles for extrinsic SERS can be applied in a variety of situations where it is difficult to take intrinsic SERS measurements. For example, nanoparticles used for extrinsic SERS can target specific cell biomarkers [15] and cancer cells [16], while intrinsic SERS applications do not have targeting capabilities. In addition, nanoparticles for extrinsic SERS are synthesized to prevent aggregation in a variety of environments [17]. This trait accommodates in vivo measurements. For example, extrinsic SERS has been used to measure in vivo liver function [18]. In contrast, nanoparticles used in intrinsic SERS applications are susceptible to aggregation, preventing analysis in certain environments.


Nanoparticle properties and synthesis effects on surface-enhanced Raman scattering enhancement factor: an introduction.

Israelsen ND, Hanson C, Vargis E - ScientificWorldJournal (2015)

An illustration of an extrinsic SERS nanoparticle for targeting of a specific antigen.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4390178&req=5

fig1: An illustration of an extrinsic SERS nanoparticle for targeting of a specific antigen.
Mentions: Extrinsic SERS is an indirect method of measuring target molecules because the acquired spectrum is of a Raman reporter rather than the target itself. A Raman reporter is a molecule that has inherently strong Raman active modes. An illustration of a nanoparticle used for extrinsic SERS is provided in Figure 1, where a Raman reporter molecule is bound to the metal surface and encased in a protective layer. This protective layer prevents nanoparticle aggregation and reporter leaching by steric hindrance and charge neutralization. The nanoparticle is then functionalized with an antibody or other ligand to target specific molecular sites. Nanoparticles for extrinsic SERS can be applied in a variety of situations where it is difficult to take intrinsic SERS measurements. For example, nanoparticles used for extrinsic SERS can target specific cell biomarkers [15] and cancer cells [16], while intrinsic SERS applications do not have targeting capabilities. In addition, nanoparticles for extrinsic SERS are synthesized to prevent aggregation in a variety of environments [17]. This trait accommodates in vivo measurements. For example, extrinsic SERS has been used to measure in vivo liver function [18]. In contrast, nanoparticles used in intrinsic SERS applications are susceptible to aggregation, preventing analysis in certain environments.

Bottom Line: However, the inherent insensitivity of the technique makes it difficult to use and statistically complicated.When Raman active molecules are near gold or silver nanoparticles, the Raman intensity is significantly amplified.This phenomenon is referred to as surface-enhanced Raman spectroscopy (SERS).

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322, USA.

ABSTRACT
Raman spectroscopy has enabled researchers to map the specific chemical makeup of surfaces, solutions, and even cells. However, the inherent insensitivity of the technique makes it difficult to use and statistically complicated. When Raman active molecules are near gold or silver nanoparticles, the Raman intensity is significantly amplified. This phenomenon is referred to as surface-enhanced Raman spectroscopy (SERS). The extent of SERS enhancement is due to a variety of factors such as nanoparticle size, shape, material, and configuration. The choice of Raman reporters and protective coatings will also influence SERS enhancement. This review provides an introduction to how these factors influence signal enhancement and how to optimize them during synthesis of SERS nanoparticles.

No MeSH data available.