Lifetime-based sensing of sodium and potassium
AssigneeUniversity of Maryland, Baltimore
InventorsJoseph R. Lakowicz, Henryk Szmacinski
Life of this patent
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Abstract
A system and method of optically measuring Na+ and K+ in a sample such as blood which contains high concentrations Na+ (up to 160 mM) and K+ (up to 6.5 mM) using a photoluminescent probe having intrinsic analyte-induced lifetime changes. Specifically, the use of lifetime-based sensing of Na+ and K+ at the extracellular concentrations present in whole blood or, blood serum. The preferred embodiment uses phase-modulation fluorometry.
Claims14
A method of optically measuring Na+ concentration in a sample containing Na+ at a concentration of above 100 mM and up to 160 mM, the sample further containing a concentration of 2.5-6.5 mM of K+, said method comprising the steps of:
- adding to a sample containing an ionic solute of Na+ a photoluminescent ligand probe capable of measuring concentration of Na+ in the sample containing Na+ at a concentration of above 100 mM and up to 160 mM, the sample further containing a concentration of 2.5-6.5 mM of K+, wherein said probe is non-covalently bound to the ionic solute of sodium to form a sodium-bound probe species, and wherein bound and unbound species of said probe exist in said sample, said probe having intrinsic sodium-induced lifetime changes;
- exciting said sample with radiation;
- detecting the resulting emission beam from said bound and unbound species;
- and
- performing a calculation utilizing the apparent luminescence lifetime of the emission to determine the Na+ concentration of said sample without utilizing fluorescence intensity in said calculation to determine the sodium concentration;
- wherein said sample is selected from the group consisting of blood and serum.
A method of optically measuring K+ concentration in a sample containing an ionic solute of K+ at a concentration of 2.5-6.5 mM, with Na+ present in a concentration of above 100 mM and up to 160 mM, said method comprising the steps of:
- adding a coumarin diacid cryptant (“CD 222”) probe to a sample to be analyzed, said sample containing K+ in an ionic solute at a concentration of 2.5-6.5 mM, and having Na+ present in a concentration of above 100 mM and up to 160 mM, wherein said probe is non- covalently bound to an ionic solute of K+ to form a K+-bound probe species, and wherein bound and unbound species of said probe exist in said sample;
- exciting the sample with radiation;
- detecting the resulting emission beam from said bound and unbound species;
- and
- performing a calculation utilizing the apparent luminescence lifetime of the emission to determine the potassium concentration of the sample without utilizing fluorescence intensity in said calculation to determine the potassium concentration;
- wherein said sample is selected from the group consisting of blood and serum.
Dependencies are inferred from the claim text.