Singlet oxygen induced advanced glycation end-product photobleaching of in vivo human fingertip autofluorescence

Bin Deng, Anabel Simental, Patrick Lutz, George Shaheen, Joseph Chaiken

Research output: Chapter in Book/Entry/PoemConference contribution

8 Scopus citations


Nonenzymatic glycation and oxidation of ubiquitous proteins in vivo leads to irreversible formation of advanced glycation end products (AGEs). Due to their relatively long half life and low clearance rate AGEs tend to accumulate within static tissues and the circulatory system. Spectra obtained using 830 nm near-infrared (NIR) excitation suggest that the so-called " autofluorescence" from all tissues has a finite number of sources but the fact that senior and diabetic subjects produce more than other members of the general population suggests that a significant portion of the total autofluorescence from all sources originates from AGEs. Using pentosidine generated in a reaction mixture as described by Monnier as representative, an in vitro study unveiled very similar fluorescence and photobleaching pattern as observed for autofluorescence in vivo. A series of oxygen, air and argon purging experiments on the pentosidine-generating reaction mixture suggests that pentosidine is a singlet oxygen sensitizer and secondary reactions between the pentosidine itself and/or other fluorophores and the photosensitized singlet oxygen explain the observed photobleaching. Ab initio Gaussian calculations on pentosidine reveal the existence of low-lying triplet excited states required for the sensitization of ground state oxygen. A commercially available product known as singlet oxygen sensor green (SOSG) that specifically serves as a singlet oxygen detection reagent confirms the generation of singlet oxygen from NIR irradiated pentosidine trimixture. This study provides one definite chemical mechanism for understanding in vivo human skin autofluorescence and photobleaching.

Original languageEnglish (US)
Title of host publicationBiomedical Vibrational Spectroscopy V
Subtitle of host publicationAdvances in Research and Industry
StatePublished - 2012
EventBiomedical Vibrational Spectroscopy V: Advances in Research and Industry - San Francisco, CA, United States
Duration: Jan 21 2012Jan 22 2012

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherBiomedical Vibrational Spectroscopy V: Advances in Research and Industry
Country/TerritoryUnited States
CitySan Francisco, CA


  • Advanced glycation end products (AGEs)
  • autofluorescence
  • near-infrared (NIR)
  • pentosidine
  • photobleaching
  • singlet oxygen

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging
  • Biomaterials


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