We designed a 1,8-naphthalimide-based chemosensor for dual-mode sensing of multiple analytes. Sensor 1 contains a hydrazone linker with a quinoline group that can generate CN⁻ and F⁻-specific color changes while exhibiting Hg²⁺-specific fluorescence enhancement. Sensor 1 demonstrated highly specific and sensitive signal changes upon binding to these ions with detection limits in the submicromolar range. We believe that sensor 1 responds to anions and cations by two distinct mechanisms, thus enabling dual-mode detection of multiple analytes.