Fig. 4. TEM images with the angle and core-to-tip measurement of AuNSs prepared by the addition of ascorbic acid after stirring the seed-growth mixture for (A) 15 minutes (scale bar 400 nm), (B) 15 minutes (a small field of view on several nanostars, scale bars 50–100 nm), (C) 20 minutes (scale bar 50 nm), and (D) 25 minutes (scale bar 100 nm). (E) High resolution TEM images with a small field of view on one-branch of the Au nanostars particle with a twinned planes. The scale bar represent 10 nm.