Light-Emitting Conjugated Organic Polymer as an Efficient Fluorescent Probe for Cu²⁺ Ions Detection and Cell Imaging

Conjugated organic polymers (COPs) have been excellent candidates because the conjugated structure occupied π structure that is useful to develop light-emitting materials. However, most COPs emitt weak luminescence owing to the H-aggregation effect. Light-emitting conjugated organic polymers (LCOP-1) possess rich butyl groups anchored in the skeleton to enhance light-emitting activity via reducing the H-aggregation effect. Owing to abundant hydroxyl and nitrogen atoms, LCOP-1 exhibits high sensitivity, selectivity, and fast response to Cu²⁺ ions within 1 min in comparison with the cations of Na⁺ , Mg²⁺ , Al³⁺ , Zn²⁺ , Cd²⁺ , Ni²⁺ , Cr³⁺ , Hg²⁺ , Fe³⁺ , Fe²⁺ , Pb²⁺ , Co²⁺ , etc. The detection limit can be down to nanomolar. Moreover, the sensor exhibits detection toward Cu²⁺ ions via a naked eye colorful change from pale-yellow to yellowish-brown. Furthermore, the light-emitting probe also successfully achieves the detection of Cu²⁺ ions in cells without cytotoxicity, indicating its great potentials in biological function.