Ag-core-Au-shell bimetallic nanocomposites: Gold shell thickness dependent study for SERS enhancement

作者：Khurana Parul; Thatai Sheenam; Prasad Surendra^*; Soni Sarvesh; Kumar Dinesh

来源：Microchemical Journal, 2016, 124: 819-823.

DOI：10.1016/j.microc.2015.10.009

• Nanocomposites
• Surface enhanced Raman scattering
• Surface plasmon resonance
• Crystal violet
• Enhancement factor

This study reports the synthesized core-shell bimetallic nanocomposites of silver and gold, respectively by varying the thickness of Au shell and studying its role in enhancing the Raman scattering of the molecule. The crystal violet (CV) was chosen as the target analyte molecule and the surface enhanced Raman scattering (SERS) enhancement of this molecule was studied as a function of Au shell thickness. The appropriate thickness of Au nanoshell, deposited on the Ag nanoparticles to obtain the maximum SERS enhancement, was identified and further increase in thickness of Au showed a decrease in intensity of the SEAS signals. Among all the fabricated Ag@Au specimens similar to 30 nm of Ag seed with 8 nm of Au nanoshell showed the maximum enhancement of the SERS signals of CV. The close proximity of discontinuous Au shell acts as SERS hot spots by creating molecular level gap that accommodates the CV molecules responsible for the SERS enhancement up to the order of 10(13) which is highly reproducible.

• 出版日期2016-1