Multi-layer device for selectively determining magnesium ion
Inventors
ZHU, Peter Chaoquan • Wu, Yingzi
Assignees
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Publication Number
US-9360474-B2
Publication Date
2016-06-07
Expiration Date
Abstract
The invention relates to devices comprising a sensor layer capable of binding magnesium ions and a scavenging layer that preferentially binds to calcium ions in the presence of both magnesium ions and calcium ions. The sensor layers can comprise known or novel luminionophores. The invention further relates to methods of selectively detecting magnesium ion concentration in the presence of calcium ions.
Core Innovation
The invention provides a device for selectively measuring the presence of magnesium ions. The device includes a substrate, a sensor layer comprising a magnesium-binding luminoionophore optionally immobilized on a solid support, and a scavenging layer that preferentially binds calcium ions in the presence of both magnesium ions and calcium ions. The luminoionophore exhibits luminescence at a first intensity and, upon contacting the device with a solution containing magnesium ions, exhibits a second intensity different from the first intensity in an amount proportional to the concentration of magnesium ion present in the solution.
The selective measurement is achieved by combining a magnesium-binding luminoionophore sensor layer with a calcium-preferential scavenging layer. In this way, the device enables luminoionophore luminescence changes that are proportional to magnesium ion concentration even when calcium ions are present.
The invention also defines luminoionophores conforming to Formula (I), with A, B, and C selected from hydrogen, −OCH2COOR′, and −N(CH2COOR′)2, R′ selected from hydrogen, C1-C12-alkyl, and a cation, X and Y independently selected from hydrogen, hydroxyl, halogen, ethoxy, methoxy, amine and −COOR′, v selected from 0 to 4, and Z defined as a luminophoric moiety of Formula (a). At least one of R3 through R8 is a −NH-group through which Z is bound to the group −(CXY)v−.
Claims Coverage
The consolidated content provides independent device and method claim groups, together with luminoionophore structure claims. Across these, the claims include a magnesium-binding luminoionophore sensor layer, a calcium-preferential scavenging layer for selective Mg2+ measurement in the presence of Ca2+, specified luminoionophore structures conforming to defined formulas, and a fluorescence-based method for deriving magnesium ion concentration from intensity differences.
Magnesium-selective device with luminoionophore sensor and calcium-preferential scavenging layer
A device for selectively measuring the presence of magnesium ions comprising a sensor layer with a magnesium-binding luminoionophore and a scavenging layer that preferentially binds to calcium ions when both magnesium ions and calcium ions are present, wherein luminescence changes from a first intensity to a second intensity upon contacting with a magnesium-containing solution in proportion to magnesium ion concentration.
Luminoionophore defined by general Formula (I) with luminophoric moiety of Formula (a)
A luminoionophore of general Formula (I) in which A, B, and C are selected from hydrogen, −OCH2COOR′, and −N(CH2COOR′)2 with at least one of A, B, and C selected from −OCH2COOR′ and −N(CH2COOR′)2; R′ selected from hydrogen, C1–C12-alkyl, and a cation; X and Y independently selected from hydrogen, hydroxyl, halogen, ethoxy, methoxy, amine, and −COOR′; v being 0–4; and Z being a luminophoric moiety of Formula (a), where R3–R8 are independently selected from hydrogen, a lipophilic group, a hydrophilic group, and a reactive group for coupling to a polymer, with at least one of R3–R8 being a −NH-group through which Z is bound to the group −(CXY)v−.
Method for determining magnesium ion concentration using fluorescence intensity change with calcium-preferential binding compound
A method of determining the concentration of magnesium ions in a sample comprising measuring a fluorescence emission mixture including a magnesium-binding luminoionophore and a compound with preferential binding affinity for calcium ions when calcium and magnesium are present to obtain a first intensity; contacting the mixture with the sample to obtain a changed first intensity; measuring the intensity of at least one fluorescence emission to obtain a second intensity; and deriving the magnesium ion concentration based, in part, on the difference between the first and second intensities.
The claim coverage centers on selective Mg2+ measurement by pairing a magnesium-binding luminoionophore sensor layer with a calcium-preferential scavenging layer, with Mg2+ responsiveness expressed as a luminescence intensity change proportional to Mg2+ concentration. The claims further define a general Formula (I) luminoionophore with luminophoric moiety Z and provide a fluorescence-based method that derives Mg2+ concentration from differences between first and second fluorescence intensities.
Stated Advantages
Selective measurement of magnesium ions in the presence of both magnesium ions and calcium ions.
Luminescence or fluorescence intensity changes in an amount proportional to the concentration of magnesium ion present in the solution or sample.
Preferential binding of calcium ions in the presence of both magnesium ions and calcium ions to enable magnesium selectivity.
Documented Applications
Measuring magnesium ions using a device that includes a magnesium-binding luminoionophore and a calcium-scavenging layer.
Determining the concentration of magnesium ions in a sample using fluorescence emission and intensity difference between first and second intensities.
Applying the method to a biological fluid.
Biological fluid selected from whole blood, plasma, serum, or urine.
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