SERS Detection of a Single Nucleobase in a DNA Oligomer Using a Gold Nanoparticle Dimer

This paper reports a surface enhanced Raman spectroscopy (SERS) of a single-stranded DNA toward SERS-based DNA sequencing. The Raman enhancing hotspot with 1-nm nanogap in the single dimer of gold nanoparticles has a space for only single DNA oligomer and enables measurements of a single nucleobase. Optimizing gold nanoparticle size, we demonstrated the detection of a single adenine in a single DNA oligomer. The time transition of adenine and cytosine peaks reflects identification of adjacent bases in a DNA oligomer sequence, suggesting the possibility of one-by-one DNA sequencing with SERS.