To generate the 1D array of gold nanowires, the anions of Au precursors were first loaded on the P2VP cylindrical domains, as described in the “SEM imaging” section (immersing the films in 5 mM HAuCl4/3% HCl solution for 30 min). After Au ion loading, an O2 reactive ion etching process (60 W, 10 mtorr, and 10 sccm) was applied for 30 s to remove the PS domains and reduce the gold ions to solid gold structure (32). The unit of flow rate (sccm) represents standard cubic centimeters per minute.