Engineering fluorescent semiconducting polymer nanoparticles for biological applications and beyond.

Semiconducting polymer nanoparticles (SPNs), derived from conjugated polymers (CPs), have emerged as a new class of soft fluorescent nanomaterials in recent years. Owing to the distinguished properties resulting from CPs and nanosize materials including extraordinary brightness, fast emission rate, strong photostability and outstanding biocompatibility, SPNs have shown potential for application in biosensing, bioimaging and biomedical areas. More importantly, in comparison to inorganic nanomaterials, SPNs hold more flexible modification approaches. These modification approaches can be performed at any stage of the preparation process of SPNs, providing great convenience and flexibility for fabricating functionalized SPNs to expand their bioapplication in various fields. In this feature article, we summarize the recent advances in the modification approaches to fabricate functionalized SPNs for bioapplications. The challenges and further outlook for fabricating functionalized SPNs are also discussed.