Acridine orange-heparin fluorescence

Aminoalkyl anthracene derivatives have already featured prominently in this discussion with regard to their proton responsive fluorescence. Some of these in their protonated form also appear in a fluorescent signalling role in association with macromolecular species which is however unconnected with PET action. These mono- or oligocations bind to polyanions such as DNA and heparin [87, 88]. On one hand, this can lead to excited state association between two sensor cations residing on the same polyanionic strand. Acridine orange with its cationic jr-system also exhibits a related behaviour which has been... 

As an example of the potential usefulness of such fractions, we also report their use as a probe of the physical basis of the photochemical fading of acridine orange bound to heparin. Fluorescence fading under continuous irradiation is a second-order photochemical reaction of adjacently-bound acridine orange ions in which photooxidation leads to irreversible loss of fluorescence, with the role of heparin being catalytic... 

J. M. Menter, R. E. Hurst, and S. S. West, Photochemistry of Heparin-Acridine Orange Complexes in Solution Photochemical Changes Occurring in the Dye and Polymer on Fluorescence Fading, Photochem. Photobiol 29, 473-478 (1979). 

Saunders, A. M. Absorption and fluorescence spectra of euchrysine GGNX and acridine orange effects of heparin, sodium chloride, and a cation exchange resin. Stain Technol. 1968, 43, 207-215. 

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