Detection of DNA, RNA Bases and Rare Bases by Terahertz Spectroscopy

Spectral analysis of nucleic acid molecular bases is of great significance to the study of biogenetics. In this paper, the feasibility of terahertz time domain spectroscopy (THz-TDS) and Raman spectroscopy for the spectroscopic detection of DNA, RNA bases and rare bases is discussed. The terahertz and Raman spectra of seven solid nucleic acid bases were analyzed, and the THz-TDS and Raman spectroscopy techniques were compared. In THz-TDS experiments, cytosine (C), guanine (G) , adenine (A) , thymine (T, DNA-specific) and uracil (U, RNA-specific) and rare bases (5-methylcytosine ( m(5)C), 1-methyladenine (m(1)A)) were identified. Signature absorption peaks and absorption intensities differ significantly in the 0. 2 similar to 2. 0 THz, and the differences of seven bases can be identified intuitively; In Raman spectroscopy, the seven bases also show many distinct characteristic peaks, however the characteristic peaks of Raman spectroscopy are complex and many, so it is not intuitive to identify many substances. The difference of absorption intensity is related to the thickness of powder, particle size and the depth of light focusing. The fluorescence of samples also interfere with Raman spectra. The laser may also damage biological samples. The experimental results show that these two technologies can identify seven common and rare bases. THz-TDS technology is superior to Raman spectroscopy in the ability to identify these seven bases, showing a relatively concise, fast and non-destructive detection performance. THz-TDS technology not only provides a fast and accurate method for the identification of DNA, RNA and rare bases, but also lays an experimental foundation for the study of biogenetics.