Large AuNRs (L-AuNRs, 28*150 nm, AR = 5.4) were synthesized following a previously-described approach. Seeds. Under very fast stirring at 30°C, 460 µL of NaBH4 (10 mM)/NaOH (10 mM) were added to a solution of 200 µL of HAuCl4 (25 mM) and 9.8 mL of CTAB (100 mM). This solution was kept under slow stirring for 1.5 hours before use. Growth. At 30°C, to 390 mL of CTAB (100 mM), 8 mL of HAuCl4 (25 mM), 2.8 mL of AgNO3 (100 mM) and 20 mL of hydroquinone (100 mM) were added. After 1 minute, 6.4 mL of seeds were added to this clear yellow solution and the reaction was kept under slow stirring at 30°C overnight. The nanorods were centrifuged at 5000 rpm for 15 minutes and washed twice with CTAC (1 mM).