8-(Pyren-1-yl)-2′-deoxyguanosine as an optical probe for DNA hybridization and for charge transfer with small peptides

8-(Pyren-1-yl)-2′-deoxyguanosine (Py-G) was incorporated synthetically as an optical probe into oligonucleotides. The Py-G group in DNA does not discriminate between any of the four natural nucleosides as a counterbase and exhibits altered optical properties in single strands versus double strands. Thus, the duplex hybridization of Py-G-modified DNA can be observed by both fluorescence and absorption spectroscopy. Moreover, Py-G in DNA can be applied as photoinducable donor for charge transfer processes with small peptides.