2-Hexylaminoethylamidonaphthalimide as Cu2+ sensor.

New fluorescent hexylaminoalkylamidonaphthalimides were synthesized and their fluorescence was investigated in different solvents. The fluorescence intensity of hexylaminoalkylamidonaphthalimides is directly related to the number of carbons in the intervening chain between the naphthalimide and n-hexylamine. Among the hexylaminoalkylamidonaphthalimides, 2-hexylaminoethylamidonaphthalimide was developed into a new fluorogenic probe. The bidentate 2-hexylaminoethylamidonaphthalimide acted as fluorescent chemosensor with a high selectivity and suitable affinity towards Cu(2+) in aqueous medium (pH 7.4). This technique of detection of Cu(2+) is highly sensitive and can detect 0.1 μM range.