Au/SBA-15-Based Robust and Convenient-to-Use Nanopowder Material for Surface-Enhanced Raman Spectroscopy

作者：Silva Rafael; Biradar Ankush V; Fabris Laura^*; Asefa Tewodros

来源：Journal of Physical Chemistry C, 2011, 115(46): 22810-22817.

DOI：10.1021/jp206824h

Powdered nanocomposite materials composed of SBA-15 mesoporous silica and different types of Au nanoparticles within the mesoporous channel pores (Au/SBA-15) are shown to serve as robust and efficient substrates for surface-enhanced Raman spectroscopy (SERS). Using the Au/SBA-15 samples as SERS substrates and 4-mercaptopyridine (4-Mpy) as SERS reporter molecule, SERS enhancement factors as high as similar to 10(5) are obtained. The degree of SERS enhancement is found to depend on the size of the Au nanoparticles as well as the synthetic procedures employed to synthesize the Au/SBA-15 materials. The high SERS enhancement given by the Au/SBA-15 as compared to any other powered SERS substrates appears to be the result of the formation of SERS "hot spots" due to the side-by-side alignment of Au nanoparticles within the cylindrical channel pores of the SBA-15 mesoporous silica host. Because of their powdered forms, longevity, simple sample preparation procedures, easily tunable surface, and high SEAS enhancement factors, Au/SBA-15 can also be expected to serve as simple and convenient-to-use substrates for SERS-based analysis of various analytes, besides 4-Mpy. Furthermore, this work demonstrates the synthesis of supported "naked" Au nanoparticles and their use as SEAS substrate directly and without any further chemical modification.

• 出版日期2011-11-24