THz time-domain spectroscopy and vibration analysis of DNA-related base molecules

The vibration modes of hydrogen bonds and intermolecular interaction appear in the THz region. Particularly, biomolecules show a unique fingerprint spectrum. We have measured the THz absorption spectra of simple base molecules like adenine (A), thymine (T), guanine (G), cytosine (C), deoxyadenosine monophosphate (dAMP), deoxyguanosine monophosphate (dGMP) and deoxyadenosine triphosphate (dATP). Each spectrum had a unique structure. Adenine and dAMP had little absorption. Cytosine and dCMP had larger absorption than the others. The fingerprint spectra and their identification with molecular orbital theory are presented.