Biomedical SERS

M.A. Ochsenkiihn, C.J. Campbell, Biomedical SERS studies using nanoshells, in Raman Spectroscopy for Nanomalerials Characterisation, ed. by C.S.S.R. Kumar (Springer, Berlin Heidelberg, 2012), pp. 51-74... 

BD Ratner, AS Hoffman. Synthetic hydrogels for biomedical applications. In JD Andrade, ed. Hydrogels for Medical and Related Applications. ACS Symp Ser 31. New York American Chemical Society, 1976, pp 1-36. 

Vo-Dinh T., Stokes D.L., Griffin G.D., Volkan M., Kim U.J., Simon M.I., Surface-enhanced Raman scattering (SERS) method and instmmentation for genomics and biomedical analysis, / Raman Spectrosc. 1999 30 785-793. 

Since its observation more than three decades ago by VanDuyne and Jeanmaire as well as Albrecht and Creighton [23, 24], SERS has been gaining popularity in analytical and physical chemistry and very recently also in the biomedical field [25-28]. The potential of SERS in bioanalytics lie in the combination of sensitivity that can be achieved [29-31] with the structural information that is generated in Raman spectroscopy as a vibrational method. In addition to the increased sensitivity, SERS offers the opportunity... 

NIR-absorbing metal nanostructures are appealing for biomedical imaging applications for reasons discussed previously, and this includes biological applications of SERS. For example, NIR-active core-shell superparticles have been prepared by the electrostatic assembly of densely packed Au nanoparticles on submicron silica spheres.34 Such superparticle probes can be implanted into mammalian cells by cationic transfection,186 and have produced SERS signals from absorbed DNA.187 Biocompatible SERS nanoparticle tags can also be used as contrast agents for in vivo detection, as previously discussed.169... 

SERS may be employed to analyze highly complex biomedical samples. Extracts obtained by homogenizing human lenses, for instance, have been investigated by SERS to. selectively probe for certain biological components, such as adenine containing molecules (5 Amp), aromatic acids (tyrosine and tryptophan) (Sokolov et al., 1991), or lens pigments (Nie et al., 1990). 

However, there are still open challenges, mainly related to the reproducibility of the methods for substrate fabrication, in particular when dealing with the formation of hot spots, which are responsible for the highest enhancement factors, but their efficiency is extremely sensitive toward small geometrical details within the nanostructure. Additionally, although portable Raman spectrometers are available, most of the published reports are based on very sophisticated instruments that will not find a place in routine analysis labs or hospitals. Thus, the use of SERS codification, particularly in biomedical applications, has a great potential, as demonstrated by many examples, but is open to new developments that will undoubtedly continue amazing us in the near future. 

Qian XM, Nie SM (2008) Single-molecule and single-nanoparticle SERS from fundamental mechanisms to biomedical applications. Chem Soc Rev 37 912... 

Schliicker S (2009) SERS microscopy nanoparticle probes and biomedical applications. ChemPhysChem 10 1344-1354... 

The high sensitivity ensured by the SERS microspectroscopy has thus stimulated many efforts in fabricating nanosensors especially suitable for biomedical applications [34]. For these, the challenge is to produce substrates with high SERS... 

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