Fig. 3

a Representative of FESEM images of sonicated commercial Au microwires with CTAB as a capping agent. b–d Indicate the individual Au microwires. e The corresponding diameter and f length distributions of the commercial Au microwires in an aqueous solution of CTAB. The average diameter and length of the Au microwires are 0.54 and 5.6 µm, respectively, indicated by the Gaussian plot (red line)