Using surface-enhanced Raman spectroscopy to probe for genetic markers on single-stranded DNA. 
Methods capable of quickly and inexpensively collecting genetic information are of increasing importance.  We report a method of using surface-enhanced Raman spectroscopy to probe single-stranded DNA for genetic markers.  This unique approach is used to analyze unmodified genes of moderate length for genetic markers by hybridizing native test oligonucleotides into a surface-enhanced Raman complex, vastly increasing detection sensitivity as compared to traditional Raman spectroscopy.  The Raman complex is formed by sandwiching the test DNA between 40-nm gold nanoparticles and a photolithographically defined gold surface.  With this design, we are able to collect characteristic Raman spectra about the test DNA and to detect genetic markers such as single-nucleotide polymorphisms (SNPs) and polymorphic regions.  Results show that strands containing one of three different types of polymorphism can be differentiated using statistically significant trends regarding Raman intensity.