DPPE-PEG350 is a PEG lipid-functional end group utilized in the synthesis of liposomes (LPs) for the design of conjugated polymer nanoparticles. These liposome nanoparticles (LNPs) feature biotin modifications and carboxyl end groups, allowing further coupling with other biomolecules. Functionalized nanoparticles are employed for targeted labeling of specific cellular proteins. Using streptavidin as a linker, biotinylated PEG-lipid-conjugated polymer nanoparticles can bind to biotinylated antibodies on cell surface receptors, enabling applications in fluorescence-based imaging and sensing.