Surface-enhanced Raman probing of biomolecules using Ag-coated porous glass-ceramic substrates

Surface-enhanced Raman scattering (SERS) of an amino acid, phenylalanine and an antifreeze glycoprotein have been probed using Ag-coated porous glass-ceramic substrates. The pore size of porous glass-ceramic was in the 50-nm to submicrometer range. The test molecules in aqueous solution were directly adsorbed onto porous glass-ceramic and dried out. The samples were then subsequently coated with an Ag overlayer film of 50 A in mass thickness. Surface-enhanced Raman spectra of phenylalanine and antifreeze glycoprotein were obtained, and they showed Raman signatures with certain changes compared to those of regular Raman spectra from aqueous solutions and solid samples. The results suggest that the phenylalanine and antifreeze glycoprotein molecules were chemisorbed onto substrate and interacted with Ag film for enhanced Raman scattering. Copyright (c) 2005 John Wiley & Sons, Ltd.