A novel carbazole-based compound 5, 3,6-bis[(N-ethylcarbazole-3-yl)-propene-1-keto]-N-ethylcarbazole has been designed, synthesized and characterized. The absorption and fluorescence spectra in solvents of different polarities prove that the compound has a distinct intramolecular charge transfer character. Compound 5 can be used as a new class of fluorescent probe or biosensor due to its sensitivity to the local microenvironment such as solvent polarity. (C) 2009 Chuan Dong. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.