Highly Selective Colorimetric/Fluorometric Dual-Channel Fluoride Ion Probe, and Its Capability of Differentiating Cancer Cells

A dual-channel naphthalimide-based chemosensor for rapid and sensitive detection of fluoride ion has been developed. Upon addition of F-, it undergoes deprotonation reaction through H-bonding interactions, and its maximum absorption wavelength is red-shifted for 214 nm to the far-red region, together with drastically quenched fluorescence. In addition, it shows high selectivity toward F- anion, thus could be used for practical applications to detecting F- in both solution and solid state. Furthermore, the fluorescence of MAI could be enhanced in protein-containing acidic environments, hence NIM could act as lysosome marker to differentiate cancer cells from normal ones in cell imaging.