Aqualuminescence of alkaline luminol in the presence of fluorescein

The light yield from both luminol and fluorescein is studied at a fixed concentration of luminol and by varying the concentration of fluorescein in 3 × 10 −2 M basic solution by direct chemical reaction as well as by aqualuminescence technique. The emission spectra of chemiluminescence and aqualuminescence of the alkaline luminol-fluorescein mixture are recorded on a Fuoss spectrograph. A 4-fold increase in the aqualuminescence intensity of luminol has been observed in the presence of fluorescein as compared to that of pure luminol. The results are explained on the basis of reactions of colour centres with the activators.