Investigation of near-infrared fluorescence and photobleaching of human volar side fingertips in vivo: antioxidants and melanin
Year: 2010
Type: article
Abstract: Noninvasive in vivo blood glucose determination in the skin of volar side of human fingertips by near-infrared (NIR) Raman spectroscopy relies on fluorescence to quantify blood volume. Fluorescence does not only come from blood, which is composed of plasma and red blood cells; in fact, most fluorescence produced by human fingertips originates in the static tissues, e.g. skin, interstitial fluid, etc.. It will soon be possible to quantify the precise contributions of red blood cells, plasma, and static tissue to the overall fluorescence emission. Observations reveal a systematic decay in fluorescence, which, if not caused by blood movement, challenges our ability to accurately determine blood glucose. In this work, it was found that the fluorescence decay was, in fact, not a result of a blood movement, but instead a chemical change of the static tissues decreasing their fluorescent properties. To identify possible photobleachable material, a series of in vitro experiments were performed on various antioxidants and the skin pigment melanin. While none of the antioxidants were found to fluoresce, it was observed that melanin fluoresces, photobleaches, and does not significantly recover its photobleaching. This allows for a deeper understanding as to the chemistry underlying the effect of photobleaching and how it may be accounted for in regards to this technique for glucose measurement.
Author: Colin Wright
Institution: Syracuse University
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W188747172