A FLUORESCENT SENSOR FOR CU2-PPM LEVEL( AT THE SUB)

Two 4-(aminoalkyl)aminonaphthalimide compounds which exhibit fluoresce nce enhancement and associated spectral changes in the presence of Cu2 +, Mn2+ and Ni2+ are reported. The compounds are believed to undergo i ntramolecular quenching by the distal nitrogen on the 4-substituent. W hen metal ions are present, this quenching mechanism is partially or w holly removed due to complexation of the metal ions with the 4-substit uent. The two compounds are particularly sensitive to Cu2+ such that c oncentrations in the 0-1 ppm range are sufficient to effect complete r estoration of the naphthalimide fluorescence. (C) 1998 Elsevier Scienc e S.A. All rights reserved.