Nanoparticles with Raman Spectroscopic Fingerprints for DNA and RNA Detection*
This chapter shows that nanoparticles functionalized with oligonucleotides and Raman labels, coupled with surface-enhanced Raman scattering (SERS) spectroscopy, can be used to perform multiplexed detection of oligonucleotide targets. Although oligonucleotides can be directly detected by SERS on aggregated particles, the structural similarities of oligonucleotides with different sequences result in spectra that are difficult to distinguish. This chapter discusses the design of nanoparticle probes that can be used for DNA (or RNA) detection. These probes consist of 13-nm-diameter gold particles functionalized with Raman dye-labeled oligonucleotides. The Raman spectroscopic fingerprint, which can be designed through choice of Raman label, can be identified after silver enhancing by scanning Raman spectroscopy. The Raman spectroscopic fingerprint offers potentially greater flexibility, a larger pool of available and nonoverlapping probes, and higher multiplexing capabilities than conventional fluorescence-based detection approaches.