http://onlinelibrary.wiley.com/doi/10.1002/adma.201401499/abstract"PGCS-NPs (40 nm) with excellent photothermal activity are developed, on the surface of which affibody peptides with specific affinity for EGFR and many small gold dots (1–3 nm) are densely presented. The IV-injected PGCS-NPs into EGFR-expressing tumor-bearing mice successfully perform targeted and photothermal therapy of cancer. It seems that the small gold dots released from disassembled PGCS-NPs are easily removed and never cause in vivo toxicity problems."
maybe 3nm, but 1nm gold particle??