Enhanced DNA Raman modes probed by SiO2 photonic crystals

Abstract

The study of large biomolecules, in particular DNA, is of practical interest. Marker bands of the Raman spectrum of DNA provide information about the conformational state and structure of the macromolecule. At the same time, when dealing with biological experiments, a small amount of DNA is available, which is why it is important to enhance the signal from DNA and find the proper substrate. However, it is difficult to enhance Raman spectra for large molecules as DNA without functionalization that could introduce changes in the DNA structure. In this work, a conventional substrate as CaF2 and a photonic crystal as a substrate with enhancer signal property and without DNA functionalization were applied. The factor of enhancement for DNA from salmon testes was reached up to 10 without Raman spectra distortion. The Raman spectral bands on different types of substrates are analyzed and compared.