Naphthalimide based fluorescent sensor for Zn2+ with high selectivity and sensitivity and its imaging in living cells

Abstract A novel 4-amino-1, 8-naphthalimide-based fluorescent sensor, with mono iminoethoxyacetic acid as receptor, was developed. It was applied successfully to detect Zn2+ in living cells. Under physiological pH conditions, it demonstrates high selectivity and sensitivity for sensing Zn2+ with about 5-fold enhancement in aqueous solution, with a characteristic emission band of 4-amino-1, 8-naphthalimide with a green color centered at 550 nm. DFT calculations shows Zn2+ is coordinated by the N and O atoms of the iminoethoxyacetic acid arms and methoxy group to form the distorted four-coordination geometry.