Laser-Driven Bubble Printing of Plasmonic Nanoparticle Assemblies onto Nonplasmonic Substrates
The use of optically controlled vapor bubbles for controlled synthesis and deposition at interfaces is a promising emerging technique, which is intrinsically limited by the ability of the system to provide enough heat for bubble formation that is typically addressed using a plasmonic substrate. Herein, a simple and fast method for laser-controlled printing of plasmonic nanoparticles onto nonplasmonic substrates is shown. The laser fluence needed to print the nanoparticle was lowest for nanoparticles in resonance with the laser wavelength, but the technique is also effective off-resonance. Hierarchical assemblies were obtained, where melting was observed up to a micron from the focal point of the laser beam. The assemblies show plasmonic properties in the unmelted region, as shown by surface-enhanced Raman scattering spectroscopy measurements. This work will lead to future studies on controlling the hierarchical structure of nanoparticle assemblies formed at the bubble interface toward applications in sensing and devices.
Thanks to Eric Hill and his nice microscope for printing plasmonic patterns.