Applied Physics B

, Volume 99, Issue 4, pp 841–851

Fluorescence properties of biochemicals in dry NaCl composite aerosol particles and in solutions

  • M. Putkiranta
  • A. Manninen
  • A. Rostedt
  • J. Saarela
  • T. Sorvajärvi
  • M. Marjamäki
  • R. Hernberg
  • J. Keskinen
Article

DOI: 10.1007/s00340-010-4073-z

Cite this article as:
Putkiranta, M., Manninen, A., Rostedt, A. et al. Appl. Phys. B (2010) 99: 841. doi:10.1007/s00340-010-4073-z

Abstract

Several fluorophores, such as tryptophan, NADH, NADPH, and riboflavin are found in airborne micro-organisms. In this work, the fluorescence properties of these biochemicals were studied both in dry NaCl composite aerosol particles and in saline solutions by means of laser-induced fluorescence. Fluorescence spectra were measured from individual, airborne aerosol particles and from solutions in cuvette. The excitation wavelength was varied in steps from 210 nm to 419 nm and the fluorescence was detected within a wavelength band of 310–670 nm. For each sample, the measured fluorescence emission spectra were combined into fluorescence maps. The fluorescence maximum of riboflavin in a dry NaCl composite particle is 20 nm red-shifted compared with the solution, whereas the maxima are blue-shifted by about 25 nm for tryptophan and 15 nm for NADH and NADPH. The molecular fluorescence cross sections have significant differences between the aerosol particles and the solutions, except for tryptophan. For NADH and NADPH the cross sections are over 20 times larger in the aerosol particles than in the solutions probably as a result of partial quenching of fluorescence in solution caused by the collision or stacking with the adenine moiety. The fluorescence cross section of riboflavin is almost 60 times larger in the solution than in the dry NaCl composite aerosol. This is probably caused by the different microenvironment around the fluorophore molecule and by the concentration quenching in the particles where the fluorescing molecules are relatively close to each other.

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • M. Putkiranta
    • 1
  • A. Manninen
    • 2
  • A. Rostedt
    • 1
  • J. Saarela
    • 2
  • T. Sorvajärvi
    • 2
  • M. Marjamäki
    • 1
  • R. Hernberg
    • 2
  • J. Keskinen
    • 1
  1. 1.Department of Physics, Aerosol Physics LaboratoryTampere University of TechnologyTampereFinland
  2. 2.Department of Physics, Optics LaboratoryTampere University of TechnologyTampereFinland

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