Highly Efficient Fluorescent Material Based on Rare-Earth-Modified Polyhydroxyalkanoates

Fluorescent materials play an important role in biomedical fields. However, the main types of fluorescent materials suffer from several disadvantages especially the biotoxicity, which largely restrict its wider applications in biological fields. In this study, a highly efficient rare-earth-modified fluorescent material was successfully designed and fabricated based on polyhydroxyalkanoates, which are known as biodegradable and biocompatible materials. A new Functional-PHA polymer was microbially synthesized by engineered Halomonas bluephagenesis and was used as a basal matrix to generate the rare-earth-modified PHA. N-Acetyl-l-cysteine-grafted PHA (NAL-grafted-PHA) was first produced via a UV-initiated thiol-ene click reaction and the rare earth metal ions (Eu³⁺ and Tb³⁺) were subsequently chelated onto the NAL-grafted-PHA through the coordination effect. The composite material exhibited intense photoluminescence properties under UV laser excitation, indicating the excellent features as fluorescent material. The enhanced hydrophilicity and superior biocompatibility of rare-earth-chelated PHA were confirmed, suggesting its great potential application value in biomedical fields.