18:1 PEG5000 PE is a PEG lipid functional end group used in the synthesis of liposomes (LPs) for designing conjugated polymer nanoparticles. These lipid nanoparticle complexes (LNPs), with biotin modification and carboxyl termini, can further couple with other biomolecules. The functionalized nanoparticles can target and label specific cell proteins. Using streptavidin as a linker, the biotinylated PEG lipid-conjugated polymer nanoparticles can bind to biotinylated antibodies on cell surface receptors, enabling fluorescence-based imaging and sensing applications.