UNENHANCED SURFACE RAMAN-SPECTRA OF SELF-ASSEMBLED MOLECULES ADSORBEDON A AU(111) SURFACE

Surface unenhanced Raman spectra were acquired from a monolayer of p-n itrothiophenol, n-octadecylmercaptan and 4-mercaptopyridine adsorbed o n an atomically smooth single crystal Au(111) surface by using 514.5 n m Ar+ laser, Triplemate monochrometer and CCD detection system. In the SER spectra of the same molecules on roughened Au surfaces, 10(6) enh ancement in cross sections of SERS was experimentally obtained compare d to the unenhanced Raman spectra. The orientations of those molecules on an atomically smooth surface were also established.