Figure 1.

Optical clearing of gold nanoparticles at liquid–liquid interfaces and transmittance modulation. (a) Schematic of a liquid–liquid interface loaded with Au NPs and its response to a laser beam. A green arrow indicates the direction of beam propagation and black arrows indicate the radial motion of interfacial Au NPs. (b) Pictures of Au NP-loaded HFE–ethanol–water interface system. (c) Transmittance spectra of the gold interface under laser illumination at varying powers. (d) Optical clearing of interfacial species visualized by a cluster of PS microparticles (scale bar: 10 μm). Green crossbars indicate the position of the laser beam. (e) Light amplitude switching under on/off cycles for different durations: 5 s/5 s, 10 s/10 s, 30 s/30 s from the top panel. The brightfield intensity was recorded at the center position of the laser beam (0.72 μm × 0.72 μm), and two notch filters were used to block the laser beam. (f) Brightfield intensity for turn-on and turn-off switching.