Lateral flow assay device and absorbent article containing same
View Patent ↗A lateral flow assay device for testing a bodily fluid, such as urine, blood, mucous, saliva, etc., is provided. The lateral flow assay device includes a chromatographic medium (e.g., porous membrane) that defines a detection zone that provides a signal indicative of the presence or amount of bilirubin or urobilinogen. The device may also include a control zone that provides a signal indicative of whether a sufficient amount of bodily fluid has been provided and tested. In one embodiment, the device is integrated into an absorbent article to provide a user or caregiver with rapid information about a health condition. For example, the device may be integrated into a diaper to provide information about the presence of bilirubin and/or urobilinogen. This information may provide an early warning system to allow the user or caregiver to seek additional testing and/or treatment. Alternatively, semi-quantitative or quantitative results may be derived from the test.
1. A diagnostic test kit for detecting the presence or amount of at least one of bilirubin and urobilinogen within a test sample, the diagnostic test kit comprising:
a lateral flow assay device, the lateral flow assay device including:
a chromatographic medium defining a detection zone within which an indicator reagent is non-diffusively immobilized, wherein the indicator reagent is capable of reacting with bilirubin or urobilinogen to generate a detection signal, wherein a reagent zone is positioned upstream from the detection zone within which is diffusively immobilized a component that facilitates the reaction of the indicator reagent with bilirubin or urobilinogen; and
an absorbent material that receives the test sample after flowing through the chromatographic medium.
2. The diagnostic test kit of claim 1 , wherein the indicator reagent is a diazonium salt or a derivative thereof.
3. The diagnostic test kit of claim 2 , wherein the diazonium salt is p-aminobenzenesulfonic acid, 2,6-dichlorobenzene diazonium tetrafluoroborate, or 2-trifluoromethylbenzene diazonium.
4. The diagnostic test kit of claim 2 , wherein the diazonium salt is 4-fluoro-3-nitrobenzenediazonium salt, 4-methoxybenzene-diazonium-tetrafluoroborate, or 3,3′-dimethoxybiphenyl-4,4′-diazonium salt.
5. The diagnostic test kit of claim 1 , wherein the indicator reagent is an Erhlich reagent or a derivative thereof.
6. The diagnostic test kit of claim 1 , wherein the indicator reagent comprises a macromolecular moiety and a reactive moiety.
7. The diagnostic test kit of claim 6 , wherein the macromolecular moiety is formed from a polymer.
8. The diagnostic test kit of claim 7 , wherein the polymer is a polysaccharide.
9. The diagnostic test kit of claim 6 , wherein the macromolecular moiety is formed from a particle.
10. The diagnostic test kit of claim 9 , wherein the particle is a carboxylated latex particle.
11. The diagnostic test kit of claim 1 , wherein the chromatographic medium is a porous membrane.
12. The diagnostic test kit of claim 1 , further comprising a sample application zone that is located upstream from the reagent zone.
13. The diagnostic test kit of claim 1 , further comprising a quenching zone located upstream from the detection zone.
14. The diagnostic test kit of claim 1 , further comprising a control zone that is capable of signaling the presence of the test sample.
15. The diagnostic test kit of claim 14 , further comprising a control reagent that is capable being detected within the control zone.
16. The diagnostic test kit of claim 1 , wherein the test sample is urine.
17. The diagnostic test kit of claim 1 , wherein the indicator reagent preferentially reacts with bilirubin to generate the detection signal.
18. The diagnostic test kit of claim 1 , the lateral flow assay device further comprising a second detection zone within which a second indicator reagent is immobilized, wherein the second indicator reagent preferentially reacts with urobilinogen to generate a second detection signal.
19. The diagnostic test kit of claim 18 , the lateral flow assay device further comprising a second reagent zone which is located down stream of the first detection zone and upstream of the second detection zone.
20. An absorbent article for receiving a bodily fluid suspected of containing bilirubin or urobilinogen, comprising:
a substantially liquid impermeable layer;
a liquid permeable layer;
an absorbent core positioned between the substantially liquid impermeable layer and the liquid permeable layer; and
a lateral flow assay device integrated into the article and positioned such that the device is in fluid communication with the bodily fluid when provided by a wearer of the article, the lateral flow assay device comprising a chromatographic medium that defines a first detection zone in which a first indicator reagent is non-diffusively immobilized, the first detection zone being configured for exhibiting a signal indicative of the presence or amount of at least one of bilirubin and urobilinogen in the bodily fluid, wherein a reagent zone is positioned upstream from the detection zone within which is diffusively immobilized a component that facilitates the reaction of the indicator reagent with bilirubin or urobilinogen.
21. The absorbent article of claim 20 , wherein the lateral flow assay device includes a control zone for indicating that a sufficient volume of the bodily fluid has been received by the lateral flow assay device.
22. The absorbent article of claim 20 , further comprising a control reagent that is capable of being detected within the control zone.
23. The absorbent article of claim 20 , wherein the absorbent article defines a window through which the detection zone, the control zone, or both is observable.
24. The absorbent article of claim 20 , wherein the lateral flow assay device further comprises a sample application zone.
25. The absorbent article of claim 24 , wherein the sample application zone is comprised of at least part of the absorbent core.
26. The absorbent article of claim 20 , wherein the lateral flow assay device is positioned between the substantially liquid impermeable layer and the absorbent core.
27. The absorbent article of claim 20 , wherein the lateral flow assay device is positioned between the liquid permeable layer and the absorbent core.
28. The absorbent article of claim 20 , wherein the first indicator reagent is a diazonium ion or a derivative thereof.
29. The absorbent article of claim 20 , wherein the first indicator reagent is an Erhlich reagent or a derivative thereof.
30. The absorbent article of claim 20 , wherein the first indicator reagent comprises a macromolecular moiety and a reactive moiety.
31. The absorbent article of claim 20 , wherein the detection zone is configured to exhibit a signal indicative of the presence or amount of bilirubin in the bodily fluid.
32. The absorbent article of claim 31 , wherein the lateral flow device further comprises a second detection zone, the second detection zone comprising a second indicator reagent, wherein the second detection zone is configured to exhibit a signal indicative of the presence or amount of urobilinogen in the bodily fluid.
33. The absorbent article of claim 20 , wherein the absorbent article is a diaper.
34. The absorbent article of claim 33 , wherein the diaper further comprises a second lateral flow assay device integrated into the article and positioned such that the second lateral flow assay device is in fluid communication with the bodily fluid when provided by a wearer of the article, the second lateral flow assay device comprising a porous membrane that defines a second detection zone, the second detection zone comprising a second indicator reagent, the second lateral flow assay device being configured for exhibiting a signal indicative of the presence or amount of at least one of bilirubin and urobilinogen in urine.
35. A method of detecting the presence or amount of at least one of bilirubin and urobilinogen within a bodily fluid, the method comprising:
providing a lateral flow assay device, the lateral flow assay device comprising a chromatographic medium that defines a first detection zone in which a first indicator reagent is non-diffusively immobilized, the first detection zone being configured for exhibiting a signal indicative of the presence or amount of at least one of bilirubin and urobilinogen in the bodily fluid, wherein a reagent zone is positioned upstream from the detection zone within which is diffusively immobilized a component that facilitates the reaction of the indicator reagent with bilirubin or urobilinogen;
contacting the lateral flow assay device with the bodily fluid; and
observing the detection zone for the visual detection signal.
36. The method of claim 35 , further comprising quantitatively or semi-quantitatively testing for the bilirubin or urobilinogen after the visual detection signal is observed.
37. The method of claim 35 , wherein the bodily fluid is urine.
38. The method of claim 35 , wherein the lateral flow assay device is disposed within an absorbent article.
39. The method of claim 38 , wherein the absorbent article is a diaper.
40. The method of claim 35 , wherein the detection zone is configured to provide a visual detection signal indicative of the presence or absence of bilirubin within the bodily fluid.
41. The diagnostic test kit of claim 1 , wherein the reagent zone is defined by a reagent pad in fluid communication with the chromatographic medium.
42. The diagnostic test kit of claim 1 , wherein the component is a buffer, surfactant, or a mixture thereof.
43. The diagnostic test kit of claim 42 , whereon the component includes an acidic buffer.
44. The absorbent article of claim 43 , whereon the component includes an acidic buffer.
45. The method of claim 35 , wherein the component is a buffer, surfactant, or a mixture thereof.
46. The method of claim 45 , whereon the component includes an acidic buffer.
47. The absorbent article of claim 20 , wherein the component is a buffer, surfactant, or a mixture thereof.