Colorimetric drug test strip using porous support material

Patent metadata

Field	Value
Publication number	US-11493451-B2
Application number	US-201916724644-A
Country	US
Kind code	B2
Filing date	Dec 23, 2019
Priority date	Dec 23, 2019
Publication date	Nov 8, 2022
Grant date	Nov 8, 2022

Abstract

A test strip includes a substantially transparent substrate and one or more colorimetric test spots on the transparent substrate. Each colorimetric test spot has one or more sensing chemicals chemically attached onto a porous support material. The porous support material has at least one exposed surface configured to absorb a body fluid. The one or more sensing chemicals are configured to change a color in response to a presence of a target drug in the body fluid.

First claim

The invention claimed is:

1. A test strip comprising:
a substantially transparent substrate; and
one or more colorimetric test spots on the transparent substrate, each colorimetric test spot comprising one or more sensing chemicals chemically attached onto a porous support material, wherein the porous support material has at least one exposed surface configured to absorb a body fluid, the one or more sensing chemicals configured to change a color in response to a presence of a target drug in the body fluid,
wherein the one or more colorimetric test spots on the transparent substrate are surrounded by the transparent substrate without the one or more sensing chemicals, and wherein the body fluid contacts the exposed surface.

2. The test strip of claim 1 , wherein the substrate is made of the porous support material and the colorimetric test spots are embedded within the substrate.

3. The test strip of claim 1 , wherein the porous support material is substantially transparent at a wavelength of light illuminating the test strip, the wavelength corresponding to the color.

4. The test strip of claim 1 , wherein the porous support material comprises an aerogel formed of inorganic silica or a polymer.

5. The test strip of claim 4 , wherein at least one of monomers and cross-linkers used for fabrication of the porous support material is hydrophilic.

6. The test strip of claim 4 wherein pores of the porous support material have an average size smaller than 20 nm.

7. The test strip of claim 4 , wherein at least one of monomers and cross-linkers used for fabrication of the porous support material is selected from a group consisting of 2-hydroxyethyl acrylate, glycerol monomethacrylate, hydroxypropyl methacrylate, N-(2-hydroxypropyl)methacrylamide; acrylic acid, methacrylic acid, 3-butene-1,2,3-tricarboxylic; β-carboxyethyl acrylate, methacryloyl-L-lysine, 4-vinylbenzoic acid; vinylsulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, styrenesulfonic acid; 2-aminoethyl methacrylate, 2-(tert-butylamino)ethyl methacrylate, N-(3-aminopropyl)methacrylamide; diallylamine, 4-vinylaniline, 2-vinylaniline; acryl amide, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, glycerol monomethacrylate, polyethyleneglycoldiacrylate, polyethyleneglycoldimethacrylate, and vinyl pyrrolidone.

8. The test strip of claim 1 , wherein the one or more colorimetric test spots comprise a multitude of particles embedded within the porous support material, the particles incorporating the one or more sensing chemicals.

9. The test strip of claim 1 , wherein the one or more colorimetric test spots comprise a block embedded within the porous support material, the block incorporating the one or more sensing chemicals.

10. The test strip of claim 1 , wherein the color change indicates detection of one or more of amphetamines, parent amphetamine molecules, methamphetamine(MA), methylenedioxymethamphetamine (MDMA), cocaine and Δ9-tetrahydrocannabinol (THC).

11. A method comprising:
collecting a sample of body fluid with an absorbent swab;
placing the swab with the collected sample into a test chamber of a test apparatus;
causing contact between the swab and an exposed surface of a test strip in the test chamber, the test strip comprising one or more colorimetric test spots that are embedded within a porous support material comprising an aerogel, wherein the one or more colorimetric test spots are surrounded by the porous support material without the one or more colorimetric test spots;
illuminating the colorimetric test spots and detecting a wavelength emitted therefrom for first and second readings, the first reading occurring just before or after the contact between the swab and the test strip and the second reading occurring a predetermined time after the contact;
based on a difference between the first and second readings that indicates a color change of the colorimetric test spot, determining a numeric value for a concentration of a drug that is correlated with the color change; and
provide an indication of the numeric value via the test apparatus.

12. The method of claim 11 , wherein the one or more colorimetric test spots comprise two or more colorimetric test spots that are illuminated simultaneously, wherein two or more respective detected individual wavelengths emitted by the two or more colorimetric test spots provide respective two or more numeric values.

13. The method of claim 11 , wherein the one or more colorimetric test spots comprise two or more colorimetric test spots that are illuminated with two or more different light sources such that two or more respective detected wavelengths are different for each colorimetric test spot.

14. The method of claim 11 , wherein the one or more colorimetric test spots comprise two or more colorimetric test spots that are illuminated in succession, and the detected wavelengths emitted are measured successively.

15. The method of claim 11 , wherein the difference between the first and second readings senses a parent molecule of the drug.

16. The method of claim 11 , wherein the body fluid comprises at least one of blood, urine, plasma, and saliva.

17. The method of claim 11 , wherein an elapsed time between the contact and the providing of the indication is less than 5 minutes.

18. The method of claim 11 , wherein the color change indicates detection of one or more of amphetamines, parent amphetamine molecules, methamphetamine(MA), methylenedioxymethamphetamine (MDMA), cocaine and Δ9-tetrahydrocannabinol (THC).

19. A system comprising:
a test strip comprising one or more colorimetric test spots each comprising one or more sensing chemicals chemically attached onto a porous support material comprising an aerogel, wherein the one or more colorimetric test spots are surrounded by the porous support material without the one or more sensing chemicals;
a swab operable to collect a sample of body fluid;
a test apparatus comprising:
a test chamber comprising an optical reader and configured to receive the test strip and at least part of the swab, wherein the swab contacts an exposed surface of the test strip;
an indicator device; and
a processor coupled to the optical reader and the indicator device and configured to perform:
detecting a wavelength of light emitted from the colorimetric test spot for first and second readings, the first reading occurring just before or after a contact between the swab and the test strip and the second reading occurring a predetermined time after the contact;
based on a difference between the first and second readings that indicates a color change of the colorimetric test spot, determining a numeric value for a concentration of a drug that is correlated with the color change; and
providing an indication of the numeric value via the indicator device.

20. The system of claim 19 , wherein the test strip comprises a substrate onto which the colorimetric test spots are placed, and wherein the porous support material has at least one exposed surface configured to absorb a body fluid, the one or more sensing chemicals configured to change a color in response to a presence of a target drug in the body fluid, wherein the substrate and the porous support material are substantially transparent at a wavelength of light illuminating the test strip, the wavelength corresponding to the color.

21. The system of claim 19 , wherein the difference between the first and second readings senses a parent molecule of the drug.

22. The system of

Assignees

• Palo Alto Res Ct Inc

Inventors

• Iftime Gabriel
• Meckler Stephen Matthew
• Schwartz David Eric
• Martini Joerg
• Rivest Jessica Louis Baker

Classifications

• B01L3/5023

  with a sample being transported to, and subsequently stored in an absorbent for analysis · CPC title

• B01L2300/0825

  Test strips · CPC title

• G01N21/8483

  Investigating reagent band (test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04) · CPC title

• B01L3/502715

  characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces · CPC title

• G01N33/523

  the element being adapted for a specific analyte · CPC title