Exploitation of planar platinum complex systems for luminescence probing of microenvironment in solution with the application to a DNA intercalation probe.

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 07455438
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 工業分析化学
• Research Institution: Tohoku University
• Principal Investigator: HOSHINO Hitoshi Tohoku Univ., Fac.of Engineering, Associate professor, 工学部, 助教授 (20124620)
• Co-Investigator(Kenkyū-buntansha): SAITOH Tohru Tokyo University of Pharmacy & Life Science, Lecturer, 生命科学部, 講師 (40186945)
• Project Period (FY): 1995 – 1996
• Keywords: Platinum complex / Room temperature phosphorescence / Luminescent probe / Microenviroment / Long lived luminescence / 長寿命発光

Research Abstract

New luminescence probes, Pt (II) chelates of 8-quinolinol derivatives are examined to be used as "probes" for microenvironments given by surfactant micelles and DNA grooves. We aimed to produce the determination system of DNA as microenviroment in vivo based on an interaction between DNA and the chelates.
We investigated the ligands 8-quinolinolate derivatives and surfactants micelles which serve as microenvironment models.
1. The mother compound 8-quinolinol and the sulfo derivatives 5-sulfo-8-quinolinol (5sox), 7-iodo-5-sulfo-8-quinolinol (ferron), and a tridentate 2-(2'-hydroxyphenyl)-8-quinolinol have been studied. The chelates of these ligands show strong red luminescence in surfactants micelle media. Particularly, Pt-ferron complex are observed to increase luminescence intensity about thirty four times in the presence of CTAC cationic surfactants micelles and sulfite ion as the remover of dissolved oxygen. The life times of the luminescence are in mu s levels (31 mu s for 5sox chelate), which are much longer than those in the ns levels of ordinary metal ion chelates. Therefore, the luminescence is room temperature phosphorescence. These results are an important knowledge to understand DNA intercalation of the probes which is the subject of future research.
2. Surfactants, cationic (quaternary ammonium type), nonionic (polyoxyethylene type and hydrophilic sugar group type), have been studied because the Pt complexes are anion or nonionic. In any surfactants, luminescence developments need the concentration of that above the CMC.A sugar type surfactant, n-dodecyl-beta-D-maltoside shows the largest enhancement of the luminescence among all surfactants examined. We expect to determine a relation between the spectroscopic properties of the luminescence Pt chelates and the chelate-micelle interactions in detail.