Ratiometric fluorescent probes for ClO− and in vivo applications

Abstract Newly synthesized 1,8-naphthalimide derivatives, 1 and 2, are found to detect specifically ClO− in presence of large excess of other competing ions with associated changes in their optical and fluorescence spectral behavior. These spectral changes are significant enough in the visible region of the spectrum and thus, allow the visual detection. The detection limit is low as 10−8 M. 1 and 2 could be used as ratiometric sensors for detection of ClO− based on the intramolecular charge transfer (ICT) process involving the donor 1,8-naphthalimide and the acceptor indolium iodide. Further, confocal laser microscopic studies confirmed that the probe 1 could also be used as imaging probe for detection of ClO− in HepG2 cells.