FOURIER TRANSFORM SURFACE ENHANCED RAMAN SCATTERING STUDIES OF TRIPLEX RNA POLY(rU).POLY(rA).POLY(rU)ADSORBED ON SILVER COLLOIDS
银胶中三螺旋RNA　　poly（rU）．poly（rA）．poly（rU）的付立叶表面增强拉曼光谱研究

Near infrared Fourier transform Raman spectroscopy was applied to characterize the triplex RNA poly(rU).poly(rA). poly(rU) in solution and adsorbed on silver colloids. Results revealed that the Watson-Crick base paired strands of the triplex RNA are in the A conformation, While the second ploy(rU) strand has a C2'-endo/anti ribose pucker. Howerver,the triplex RNA M a very strong enhanced effect of Raman signals after adsorbed on colloidal silver surfaces, the surface enhanced factor is up to 2×104. Compared to the results obtained with the triplex RNA in solution, the doublet bands located at 835 and 819cm-1indicate that the belieal structure of the triplex molecules adsorbed on silver surfaces was also Well preserved, and the adsorbed triplexes take on a conformation which is similar to that of the triplex in solution. Moreover, the negatively charged phosphate group of the ribose backbone of the triplex was anchored at the colloidal silver surface.