Analytical Sciences

Abstract − Analytical Sciences, 23(7), 891 (2007).

Effects of a Magnetic Force on Surface-Enhanced Raman Spectra of a Cysteamine Linking Magnetic Particle and a Silver Colloid Plate
Takeyoshi GOTO, Shigeki YAMAMOTO, and Hitoshi WATARAI
Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
The effects of a magnetic force on magnetic particles linked by cysteamine to a silver colloid plate were analyzed with surface-enhanced Raman scattering spectroscopy. Cysteamine molecules were stretched by a force exerted on the magnetic particles with the external magnetic field gradients generated by two Nd-Fe-B magnets. The spectra showed that the relative intensity ratio of C-S (trans) to C-S (gauche) of cysteamine was increased 2 - 3 times within 30 min under the application of magnetic field gradients. Also, the shift of C-S (T) was observed up to 4 cm-1 to higher frequency. These results suggested that an extension of the distance between a magnetic particle and a silver colloid induced isomerization from the gauche conformation to the trans conformation, accompanied by probable thiolate migration on the silver colloid surface.