4-Amino-1,8-naphthalimide-based fluorescent sensor with high selectivity and sensitivity for Zn2 + imaging in living cells

A new 4-amino-1,8-naphthalimide-based fluorescent sensor with iminodiacetic acid as receptor, was synthesized and characterized. Under physiological pH conditions, it demonstrates high selectivity and sensitivity for sensing Zn2 + with about 50-fold enhancement in fluorescence intensity. The fluorescent sensor exhibited a characteristic emission band of 4-amino-1,8-naphthalimide with a green color centered at ~ 550 nm and was successfully applied to image Zn2 + in living cells. Upon sensing of Zn2 + the fluorescence emission spectrum is “switched on” demonstrating the suppression of PET from the receptor to the fluorophore.