We synthesized novel push-pull-type fluorescent guanosine derivatives, (CN)G and (Ac)G containing 1,6- and 2,7-disubstituted pyrene chromophores. 1,6-Disubstituted pyrene derivatives, 1,6-(CN)G (3b) and 1,6-(Ac)G (3c), exhibited highly solvatochromic fluorescence emission at longer wavelength (similar to 540 nm). The environmentally sensitive fluorescent deoxyguanosines such as 3b and 3c can be used as powerful tools for structural studies of nucleic acids and molecular diagnostics. (C) 2010 Elsevier Ltd. All rights reserved.