Plastic waste was transformed into high-performance quantum dots (QDs), combining technological innovation with a focus on environmental sustainability. The excellent fluorescence properties of the synthesized quantum dots were utilized to detect Fe and F ions with high sensitivity and selectivity in an "on-off-on" dual-mode fashion. Additionally, the synthesized quantum dots exhibited stable solid-state fluorescence, enabling their use in solid-phase applications without the typical fluorescence loss observed in other materials. The versatility and tunability of the synthesized materials were demonstrated by producing three different emission colors, achieved through the incorporation of various heteroatoms during the synthesis process. This solid-state fluorescent material provides a pathway for sensing and optoelectronic applications, as well as advanced optical devices with customizable designs in the future.