Based on a perylene diimide derivatives (PDIs) platform, AM-PDIs was rationally designed and synthesized as a new colorimetric and ratiometric fluorescent sensor for naked-eye detection of fluoride ion with high selectivity over other halide ions. Addition of fluoride ion to a dichloromethane (DCM) solution of AM-PDIs resulted in an obvious color change (from red to blackish green) because of a large red shift (151 nm) in absorption. The recognition ...