Fluorescein-Modified Carbon Dioxide-Based Polycarbonate as a Biocompatible Fluorescent Probe for Detecting Ferric Ions and Intracellular Imaging

The development of novel fluorescent probes for Fe3+ ions that exhibit high selectivity, sensitivity, and biocompatibility presents a significant challenge in the field. In response to this challenge, we have designed and synthesized a green fluorescent polycarbonate (PPCF) by utilizing carbon dioxide and epoxides, incorporating fluorescent functional groups. This polymeric fluorescent probe demonstrates a high degree of selectivity for detecting Fe3+, with minimal interference from other prevalent ions. The fluorescence intensity displays robust linear correlation with Fe3+ concentration over the span of 20–200 μM, thereby enabling quantitative analysis. Furthermore, the fluorescence quenching effect induced by Fe3+ results in a detection limit of 262 nM, which is competitive with existing fluorescent probes for Fe3+ detection. Additionally, CCK-8 assays indicate that PPCF4 possesses a high safety threshold at elevated concentrations and exhibits favorable biocompatibility, essential for in vivo Fe3+ detection. Successful fluorescent imaging of Fe3+ within HeLa cells has also been accomplished. This research presents an environmentally sustainable and effective strategy for the detection of Fe3+ and for fluorescent imaging within cellular contexts using fluorescent probes.