Optics and Spectroscopy

, Volume 107, Issue 2, pp 275–281

Subnanosecond spectrofluorimetry of new indolocarbazole derivatives in solutions and protein complexes and their dipole moments

  • N. A. Nemkovich
  • Yu. V. Kruchenok
  • A. N. Sobchuk
  • H. Detert
  • N. Wrobel
  • E. A. Chernyavskiĭ
Condensed-Matter Spectroscopy

DOI: 10.1134/S0030400X09080189

Cite this article as:
Nemkovich, N.A., Kruchenok, Y.V., Sobchuk, A.N. et al. Opt. Spectrosc. (2009) 107: 275. doi:10.1134/S0030400X09080189

Abstract

The spectral and temporal characteristics of new 6,12-dimethoxyindolo[3,2-b]carbazole, 5,11-dimethyl-6,12-dimethoxyindolo[3,2-b]carbazole, and 5,11-dihexyl-6,12-di(hexyloxy)indolo[3,2-b]carbazole fluorescence probes in organic solvents and protein complexes are studied. The dipole moments of indolocarbazoles in 1,4-dioxane were measured by electrooptical absorption method. The measured dipole moments have values within the range of (3.1–3.6) × 10−30 C m in the equilibrium ground state and increase to (4.8–5.6) × 10−30 C m after excitation. The excited state lifetime of indolocarbazole derivatives increases with increasing polarity and viscosity of the environment. The binding of indolocarbazoles with trypsinogen and human serum albumin increases the fluorescence intensity, changes the intensity ratio of fluorescence bands, and increases the average excited state lifetime of indolocarbazoles. The analysis of the instantaneous fluorescence spectra and fluorescence decay parameters at different wavelengths revealed the existence of several types of probe binding sites in proteins. It is found that the fluorescence characteristics of indolocarbazole derivatives depend on the conformation rearrangements of trypsinogen due to its thermal denaturation.

PACS numbers

78.40.Dw78.40.Me

Copyright information

© Pleiades Publishing, Ltd. 2009

Authors and Affiliations

  • N. A. Nemkovich
    • 1
  • Yu. V. Kruchenok
    • 1
  • A. N. Sobchuk
    • 1
  • H. Detert
    • 2
  • N. Wrobel
    • 2
  • E. A. Chernyavskiĭ
    • 3
  1. 1.Stepanov Institute of PhysicsNational Academy of Sciences of BelarusMinskBelarus
  2. 2.Institute of Organic ChemistryJohannes Gutenberg UniversityMainzGermany
  3. 3.Research Institute of Physicochemical ProblemsBelarussian State UniversityMinskBelarus