Morphology controllable synthesis of silver nanoparticles: Optical properties study and SERS application

In this paper, we report the controllable preparation of silver nanoparticles with plate-like and granule-like morphologies using mixed solvent of ethanol and water. The dosage of water was found to be critical on the morphologies and sizes of the final silver nanoparticles. Optical measurements reveal that the plate-like silver nanoparticles possess relatively high transmittance, while the granule-like ones show low transmittance and high absorption. In addition, after binding with rhodanine, the silver nanoparticles exhibit selective enhancement for different bands as SERS substrate. The Raman bands at ca. 660 cm−1 is higher for plate-like nanoparticles, while the Raman bands at ca. 1184 cm−1 is stronger for granule-like nanoparticles.