EGF and brain neoplasm: modified EGF peptides on the surface of the photosensitizer Pc4 and coupled them to the surface of gold nanoparticles (AuNPs) to prepare functional AuNPs with the ability to target PDTs, and found that the EGF peptides interacted specifically with EGFR, which is overexpressed on the surface of brain tumor cells, to increase intracellular Pc4 uptake tenfold.