The solution was gently mixed for 10 s and left undisturbed for 3 h in an incubator at 35 C. The nanorod solution was centrifuged at 16,000 rpm for 15 min to stop the reaction. The supernatant was removed and the precipitate was re-suspended in ultrapure water. In comparison, the bAuNRs were synthesized by a
common seed-mediated method in CTAB solutions as reported previously