Fabrication of silver dendrite fractal structures for enhanced second harmonic generation and surface-enhanced Raman scattering

Abstract

Here, we prepared silver (Ag) dendrite fractal nanostructures by a facile electrochemical deposition method. The silver dendrite fractal nanostructures exhibit multiple plasmon resonances, which leads to an enhanced second harmonic generation (SHG). Interestingly, the prepared thin film can be used as plasmonic substrates. As an example application, we selected surface-enhanced Raman scattering (SERS) spectroscopy with tunable sensitivity. Using 1,4-benzenedithiol (1,4-BDT) as a probe molecule, the SERS intensity of dendrite fractal nanostructures is approximately 77 times larger than that of the flower-like nanoplates (one of the structures that appears during the growth), and a low detection limit of 10−14 M 1,4-BDT can be achieved. Our results offer a low-cost and easy strategy in fabricating nonlinear photonic nanodevices and SERS chips.