Two-color two-laser fabrication of gold nanoparticles in a PVA film

We developed a new method for the fabrication of gold nanoparticles (AuNps) in a poly(vinyl alcohol) film using a two-color two-laser irradiation. The benzophenone ketyl radical (BPH) in the excited state (BPH(D1)) was used as a reducing agent. Although BPH in the ground state also reduced AuCl4- to produce AuNps, the formation of AuNp was significantly enhanced by the BPH(D1) generated by the two-color two-laser irradiation. Because the electron transfer from the BPH(D1) to AuCl4- enhanced the formation of AuNps.