Laser-induced photochemical synthesis of branched Ag@Au bimetallic nanodendrites as a prominent substrate for surface-enhanced Raman scattering spectroscopy

The project of wielding laser light as a versatile tool for sculpting branched Ag@Au bimetallic nanocrystals with mean size of similar to 50 nm has been developed in this work. The moderate overgrowth of Ag species with negligible damage effect on the branched Ag@Au nanostructures was achieved by laser-induced photo-oxidation. The final Ag@Au nanodendrites exhibit superior surface enhanced Raman scattering (SERS) activities with an enhancement factor up to similar to 10(11) and a detection limit as low as similar to 10(-14) M. The pronounced feature should be attributed to the noticeable small-sized branches (<10 nm) and unique pronounced inter- metallic synergies. Our results have a promising potential for developing SERS- based ultrasensitive probes in biomedical application. (C) 2017 Optical Society of America