ENHANCED FLUORESCENCE FROM ORTHO-PHTHALALDEHYDE AND FLUORESCAMINE FLUOROPHORES USING TRITON AND BETA-CYCLODEXTRIN

Mexiletine- and lysine hydrochloride-o-phthalaldehyde and mexiletine hydrochloride-, cysteine-, cysteamine-, homocysteine- and lysine hydrochloride-fluorescamine derivatives were subjected to Triton and β-cyclodextrin enhancement treatments. Of several classical fluorescence-enhancing reagents tested (Triton, β-cyclodextrin, sodium dodecyl sulphate, Brij), Triton provided the best results, followed by β-cyclodextrin. Increases in fluorescence emission by a factor of up to about 10 (mexiletine-fluorescamine-Triton X-100) were observed, with a generally negligible influence of the enhancing reagents on the excitation and emission maxima. Fluorescence enhancement by the addition of a suitable reagent solution to the final analyte solution may, in specific instances, enhance the detectability of native or chemically induced fluorophores. © 1990.