A new detector for metal cations based on the combined effect of photoinduced electron transfer and a light harvesting system

A new tripod comprising three 1,8-naphthalimide units having different substituents at C-4 of the naphthalimide structure has been synthesized. The new dendron has two 4-ethoxy-1,8-naphthalimide units as an energy donor and a 4-N,N-dimethialaminoethilenidamino-1,8-naphthalimide acceptor to facilitate the donor–acceptor energy transfer. The main photophysical characteristics of the dendron have been studied in organic solvents of different polarity. The established energy transfer efficiency of is about 99% revealing the excellent antenna capacities of the dendron. The fluorescence intensity of the dendron has been studied in an acetonitrile solution in the presence of metal ions of various nature (Cu2+, Co2+, Zn2+, Ni2+, and Pb2+) using two different excitation wavelengths of 365 nm and 435 nm. The detection limit of metal cations has been determined.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights• Synthesis of new dendron containing 1,8-naphthalimide with different substituents at C-4 position. • The new dendron has an antenna effect. • They are an enhance of photoinduced electron transfer by light harvesting systems. • The new dendron is very sensitive for detection of metal cations.