title: A novel approach to blood plasma viscosity measurement using fluorescent molecular rotors.
abstract: Molecular rotors, a group of fluorescent molecules with viscosity-dependent quantum yield, were tested for their suitability to act as fluorescence-based plasma viscometers. The viscosity of samples of human plasma was modified by the addition of pentastarch (molecular mass 260 kDa, 10% solution in saline) and measured with a Brookfield viscometer. Plasma viscosity was 1.6 mPa x s, and the mixtures ranged up to 4.5 mPa x s (21 degrees C). The stimulated light emission of the molecular rotors mixed in the plasma samples yielded light intensity that was nonoverlapping and of significantly different intensity for viscosity steps down to 0.3 mPa x s (n = 5, P < 0.0001). The mathematical relationship between intensity (I) and viscosity (eta) was found to be eta = (kappaI)(nu). After calibration and scaling the fluorescence based measurement had an average deviation versus the conventional viscometric measurements that was <1.8%. These results show the suitability of molecular rotors for fast, low-volume biofluid viscosity measurements achieving accuracy and precision comparable to mechanical viscometers.
authors.affiliation: Department of Bioengineering, University of California San Diego, La Jolla, California 92093-0412, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Haidekker
authors.forename: Amy G
authors.initials: AG
authors.lastname: Tsai
authors.forename: Thomas
authors.initials: T
authors.lastname: Brady
authors.forename: Hazel Y
authors.initials: HY
authors.lastname: Stevens
authors.forename: John A
authors.initials: JA
authors.lastname: Frangos
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Theodorakis
authors.forename: Marcos
authors.initials: M
authors.lastname: Intaglietta
mesh_terms: D001809:Blood Viscosity; D005453:Fluorescence; D005456:Fluorescent Dyes; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives; D007202:Indicators and Reagents; D008433:Mathematics; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D006895:Hydroxyethyl Starch Derivatives; D007202:Indicators and Reagents