a one-“spot” seedless method is developed to synthesize 7 nm diameter AuNRs (designated sAuNRs) which enable efficient cell uptake in cell-mediated PTT applications.Compared to the more common 14 nm diameter AuNRs (designated bAuNRs), the sAuNRs have similar SPR bands and photothermal properties but better biocompatibility and higher cell uptake to macrophages.