18:0 mPEG3000 PE (ammonium) is a PEG lipid with functional end groups for synthesizing liposomes (LPs) and designing conjugated polymer nanoparticles. These liposomal nanoparticles (LNPs), featuring biotin modifications and carboxyl ends, facilitate further coupling with other biomolecules. The functionalized nanoparticles are useful for targeted labeling of specific cell proteins. Using streptavidin as a linker, biotinylated PEG lipid-conjugated polymer nanoparticles can bind to biotinylated antibodies on cell surface receptors, offering practicality for fluorescence-based imaging and sensing.