Perylenebisimide-linked nitroxide for the detection of hydroxyl radicals

A new type of fluorophore-linked nitroxide for the detection of hydroxyl radical ((OH)-O-center dot) was synthesized using perylene-3,4,9,10-tetracarboxyl bisimide and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). This new fluorescent probe, indicated here as Spy-OH (swallow-tailed perylene derivative for detecting (OH)-O-center dot) has its natural fluorescence effectively reduced due to the quenching caused by the presence of the nitroxide radical in its structure. In the presence of (OH)-O-center dot, in media containing DMSO, a conspicuous increase in the fluorescence intensity was observed. No significant change in the fluorescence intensity was observed upon the addition of other several reactive oxygen species (ROS) except for (OH)-O-center dot. Spy-OH maxima excitation and emission wavelengths lie in the visible region (520/530 nm), therefore, this fluorescent probe is expected to be useful for a simple and selective detection of (OH)-O-center dot, especially for biosamples. (C) 2009 Elsevier B.V. All rights reserved.