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Proceedings Paper

Fluorescence sensing of glucose
Author(s): Leah Tolosa; Ignacy Gryczynski; Lisa Randers-Eichhorn; Jonathan D. Dattelbaum; Govind Rao; Joseph R. Lakowicz
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Paper Abstract

We devised an optical assay for glucose based on the genetically-engineered glucose/galactose binding protein (GGBP) from E. coli and phase-modulation fluorometry. A single cysteine mutation was introduced at position 26 of GGBP. When labeled with the sulfhydryl-reactive probe I-ANS, GGBP showed a more than 50% decrease in florescence intensity with increasing glucose concentration (Kd approximately 1 (mu) M). This is consistent with the glucose-bound structure of GGBP where residue 26 becomes more exposed to the aqueous media. Since minimal lifetime changes were observed with glucose binding, a modulation sensor was devised wherein a long lifetime ruthenium metal-ligand complex (Ru) was painted on the surface of the cuvette containing ANS26-GGBP. Glucose binding resulted in changes in the relative intensities of ANS26-GGBP and Ru which were observed as dramatic changes in the modulation at a low frequency of 2.1 MHz. The modulation measured at 2.1 MHz accurately determines the glucose concentration to plus or minus 0.2 (mu) M.

Paper Details

Date Published: 3 May 1999
PDF: 6 pages
Proc. SPIE 3602, Advances in Fluorescence Sensing Technology IV, (3 May 1999); doi: 10.1117/12.347544
Show Author Affiliations
Leah Tolosa, Univ. of Maryland School of Medicine/Baltimore (United States)
Ignacy Gryczynski, Univ. of Maryland School of Medicine/Baltimore (United States)
Lisa Randers-Eichhorn, Univ. of Maryland/College Park (United States)
Jonathan D. Dattelbaum, Univ. of Maryland/Baltimore (United States)
Govind Rao, Univ. of Maryland/Baltimore (United States)
Joseph R. Lakowicz, Univ. of Maryland School of Medicine/Baltimore (United States)


Published in SPIE Proceedings Vol. 3602:
Advances in Fluorescence Sensing Technology IV
Joseph R. Lakowicz; Steven A. Soper; Richard B. Thompson, Editor(s)

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