UV-light-assisted synthesis of CeB6@Ag nano-trees for SERS application

The conventional methods of using surfactants to synthesize noble metal nanoparticles usually introduce residues on the surface, which inevitably decreases nanoparticles’ surface enhanced Raman scattering (SERS) performance. Herein, we propose a surfactant-free and feasible approach of preparing cerium hexaboride-Ag nano-trees hybrids (CeB6@Ag nano-trees) as the SERS substrate. First, the CeB6 was synthesized by a one-pot ionothermal method. Secondly, the CeB6 powder and silver nitrate were dispersed in an aqueous solution. Thereafter, the Ag+ was reduced by the UV-light assisted photoreaction and deposited on the surface of the CeB6. The SERS performance of the CeB6@Ag nano-trees was evaluated by using the Rhodamine 6G as the Raman reporter. It shows that CeB6@Ag nano-trees exhibit good SERS sensitivity with the enhancement factor of 2.45 × 107 and detection limit of 10−10 mol/L. Moreover, uniformity evaluation of the SERS signal intensity on the substrate also shows that relatively good relative standard deviation values of 12.6% (Raman peak@612 cm−1) and 14.1% (Raman peak@1652 cm−1) can be achieved. Finally, finite element simulation evidences that excellent SERS performance of the CeB6@Ag nano-trees is produced by the strong coupled localized surface plasmon resonance generated under the Raman laser irradiation.