SERS tag

Li WB, Guo YY, Zhang P (2010) General strategy to prepare Ti02-core gold-shell nanoparticles as SERS-tags. J Phys Chem C 114(16) 7263-7268... 

Fig. 11.10 A representative imaging scheme using SERS multiplexing, (a) A general concept scheme. Distribution of several targets can be imaged from a single scan by Raman intensity mapping of specific SERS band of each SERS tag, and (b) an example by Woo et al. [71]. The three different SERS intensity maps correspond to distributions of CD34, Sca-1, and SP C proteins on tissue sample. They were obtained by single scan at the pre-selected area...

Fig. 11. 13 Various types of SERS tags, (a) Utilization of bifunctional reporter [81], (b) glass-coated, analyte-tagged gold nanoparticles (GANs) [87], (c) hollow-type gold nanoparticle [36], (d) aggregates of a few silver nanoparticles (COINs) [34], (e) encapsulated SERS tag with silver nanoparticle-embedded silica core (SERS Dot) [33], and (f) pegylated gold nanoparticle [88]...

Several SERS tags have been successfully applied to imaging such as cells and tissues. Wabuyele et al. demonstrated the potential of SERS-based imaging... 

A prototype portable Raman spectrometer has been developed for detection of microbial DNA. The pathogen genomic DNA was captured by probe conjugated magnetic bead and detected by probe conjugated SERS tag under Raman spectrometer. 

Bimetallic nanomaterials Currently used monometallic SERS tags such as gold and silver NPs have a main drawback in that the metal surface is unprotected. The assays are therefore unreliable as components of the analyte can adsorb on the metal surface, leading to the possibility of replacing the label species. One way to overcome this problem is to encapsulate the metal particle/label molecule in a protective shell. Bimetallic nanostructures, with two different metals in a single particle, such as core-shell-type nanomaterials are gaining importance as Raman tags [1]. 

Y. Wang, B. Yan, L. Chen, SERS tags novel optical nanotags for bioanalysis. Chem. Rev. 113, 1391 (2013)... 

Ffe. 5.1 Schematic illustration of different approaches for SERS biomolecular detection, a Intrinsic detection of biomolecule (protein), b Extrinsic detection of labelled biomolecule (DNA). c Extrinsic detection of biomolecule using SERS tag (metallic NP with RRM). d SERS tag (metallic NP with RRMs, protective shell and antibody) for immunoassay (adapted from Wang et al. 2013. Copyright 2012 American Chemical Society)... 

Various terms for SERS tag can be found in literature, e.g. SERS nanotag, SERS probe, SERS-encoded NP, SERS label, extrinsic Raman labels (ERLs). 

Fig. 5.7 The extrinsic DNA hybridization scheme using a SERS tag. See text for details (adapted from Cao et al. 2002. Copyright 2002 The American Association for the Advancement of Science)...

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