OBSERVATION AND ANALYSIS OF SERS SPECTRUM OF LYSOZYME ON SILVER COLLOID

Author Institution: Department of Chemistry, Wuhan University; Center of Analysis and Measurement, Wuhan University; Department of Chemistry, Wuhan UniversityThe SERS spectrum of lysozyme on silver colloid was obtained. The sample solution was prepared by mixing O-2 ml silver colloid with 0.2 ml lysozyme. In the solutionn, the concentration of lysozyme was 6$\times10^{-2}$TM, chloride (I) was about $1\times10^{-3}$M and PH was 2.0. In the spectrum, the bands at 356, 424, 660, 828, 928, 978, 1190 and $1592 cm^{-1}$ were assigned to the p-hydroxyphenyl ring vibrations of tyrosine. The bands at 424, 620, 928, 1190 and $1508 cm^{-1}$ were assigned to the vibrations of phenylalanine. The bands at 760, 928, 1358, $1562 cm^{-1}$ due to the vibrations of tryptophan. The band at $238 cm^{-1}$ was the interface vibration. The S-S bond peak was observed at $518 cm^{-1}$ and it was very weak. The amide I, II, III band were observed at 1646, 1528 and $1280 cm^{-1}$, respectively. The band at $928 cm^{-1}$ was the skeletal vibration ($C_{O}$-C-N stretching). These suggested that lysozyme molecules adsorbed on the colloidal silver particales with the part of $\alpha$-helix conformation. This also confined that, as same as the normal Raman spectroscopy, the SERS spectrum could be used to obtain the valuable information of the macromolecules

OBSERVATION AND ANALYSIS OF THE SERS SPECTRA OF TETRAPHEYLPORPHINE(TPP) AND IRON(Π)IRON(\Pi) PROTOPORPHYRIN (Fe(Π)PP)(Fe(\Pi)PP)

1. T. M. Cotton, s. G. Schultz and R. P. Van Duyne, J. Am. Chem. Soc. 104(24), 6528(1982). 2. Yoshihiro Kobayashi and Koschi Itoh, J. Phys. Chem. 89, 5174(1985). 3. L. A. Scanches and T. G. Spiro, J. Phys. Chem. 89, 763(1985). 4. J. J. Memahon, S. Baer and C. A. Meleudres, J. Phys. Chem. 90, 1572(1986).Author Institution: Department of Chemistry, Wuhan University; Center of Analysis and Measurement, Wuhan UniversityThe SERS spectra of tetrapheylporphine(TPP) and iron ($\Pi$) protoporphyrin IX $(Fe(\Pi)PP)$ were obtained. Comparing of these two spectra, the bands 994, 1126, 1174, $1218cm^{-1}$ in spectra of TPP assigned to $v(C_{*} - C_{m}), v(C_{*} - N)$ were disappeared or the bands intensity decreased in SERS spectra of $Fe(\Pi)PP$. The band $1480cm^{-1}$ assigned to $v(C_{*}=-C_{*})$ in spectra of TPP was also disappeared in spectra of $Fe(\Pi)PP$. In the region of $1500-1700cm^{-1}$, there were three bands 1544, 1584, $1514cm^{-1}$ for TPP and two bands 1578, $1632cm^{-1}$ for $Fe(\Pi)PP$. Moreover, the band $1578cm^{-1}$ was enhanced intensity comparing with $1632cm^{-1}$ in SERS spectra of $Fe(\Pi)PP$. All these information indicated that, the porphyrin ring of TPP adsorbed on the surface of silver colloid by the four N atoms. But, for the $Fe(\Pi)PP$, since the four N atoms have complexed with $Fe(\Pi)PP$, the vibration modes of $v(C_{*}-C_{m}), v(C_{*}-N)$ were disappared

THE SERS SPECTRA OF BILIRUBIN AND BILIVERDIN

$^{1.}$ Rwdolf Holse, Z. Phys. Chem., 160, 45(1988). 2. B. N. Respondewski, D. L. Farrens, T. M. Cotton and P.-8. Song, FEBS Letts., 258(1), 1 (1989). 3. L. Margulies and M. Toporowics, J. Am. Chem. Soc., 106, 7331 (1984). 4. R. E. Halt, D. L. Farrens, P.-8. Song and T. M. Cotton, J. Am. Chem. Soc. 111, 9156 (1989).Author Institution: Department of Chemistry, Wuhan University; Center of Analysis and Measurement, Wuhan UniversityThe SERS spectra of oxidized bilirubin (oxidized by oxygen in alikline solution) and biliverdin were obtained. The similarity of these two SERS spectra demonstrated that the bilirubin was oxidised to biliverdin by oxygen in amibent temperature. The informations of these SERS spectra also show that the orientation of bilirubin and biliverdin on surface of silver colloid were different. In the experimental case, the internal hydrogen of bilirubin was formed with the interplanar angle $98^{\circ}$ of the two pyrromethnone rings. The bilirubin was intercalated into the silver colloid with the lactam ring slit on surface slightly. The biliverlin was flat on the surface of silver colloid with the N atom of pyrrole ring C and O atom of lactam ring D prontonated. On the surface of silver colloid the biliverdin adopt a near planar and cyclic helical conformation. And the ring C and D of biliverdin were most near the surface of silver colloid

THE SERS STUDIES OF 8-HYDROXYQUINOLINE(I) COMPLEXED WITH ALUMINIUM(Π\Pi) AND IRON(Π\Pi)

$^{1.}$ S. C. Wait and J. C. McNerey, J. Mol. Spectrosc. 34, 56 (1970). 2. M. Moskovits and J. S. Suh, J. Phys. Chem. 92(22), 6327 (1988).Author Institution: Department of Chemistry, Wuhan University; Center of Analysis and Measurement, Wuhan UniversityThe 8-hydroxyquinoline was used as a analysis reagent in spectrophotometric study. It could complex with many transition metal ions, such as aluminium, iron, copper and nickel. Here, the SERS spectra of 8-hydroxyquinoline and its complex with $Al(\Pi$) and $Fe(\Pi$) were obtained. By contrast, the bands $1322, 1466, 1494cm^{-1}$ were enhanced and the band $1560cm^{-1}$ reduced in intensity for complex of I with Fe($\Pi$). The sharp bands $830, 1004cm^{-1}$ and medium intensity bands $1138, 1250cm^{-1}$ were appeared in the SERS spectra of I with $Al(\Pi)$ complex. But the intensity of bands $1358, 1360cm^{-1}$ and $1590cm^{-1}$ assigned to v (C-C) and v (ring) vibration modes were decreased. These confirmed that, on the surface of silver colloid partiel, the gemotery of 8-hydorxyquinoline in the complex with $Fe(\Pi)$ or $Al(\Pi)$ were different. The bands $1322, 1466, 1494cm^{-1}$ were assigned to characteristic bands of I with $Fe(\Pi)$ complex. The bands $830, 1004cm^{-1}$ were assigned to the marked bands of I with $Al(\Pi)$ complex. The detect limit of I with $Al(\Pi)$ and $Fe(\Pi)$ complexes could be reduced to 4ug/ml and 8ug/ml, respectively