Methods and apparatus for detecting compounds in liquids

Abstract

Described herein are apparatus and methods for detecting substances of abuse or other analytes in liquids. For example, the apparatus and methods described herein can be used for real-time detection of analytes, such as substances of abuse. The methods comprise providing a detection area comprising a chromatographic membrane capable of receiving the liquid and allowing for migration of the liquid, the chromatographic membrane comprising an anti-analyte antibody-particle conjugate, an analyte-conjugate protein at a test line; exposing at least the first location of the apparatus to the liquid; and determining whether an interaction between the analyte-conjugate protein and the liquid occurs to detect the presence of the analyte. The chromatographic membrane may further comprise an anti-species antibody at a control line. Specific buffers are disclosed, and these buffers may be used in the preparation of the apparatus to overcome challenges associated with miniaturization and challenges associated with exposure to beverages.

1 . An apparatus for detecting the presence of an analyte in a liquid, the apparatus comprising a lateral flow assay capable of receiving a sample of a beverage and analyzing the beverage for the presence of the analyte. 
     
     
         2 . The apparatus of  claim 1 , wherein the lateral flow assay comprises: a sample area, a conjugate area, and a detection area, wherein at least one of the sample area, conjugate area, or detection area comprises at least one residual buffer composition. 
     
     
         3 . The apparatus of  claim 2 ,
 wherein the conjugate area comprises at least one anti-analyte antibody-particle conjugate or anti-analyte aptamer-particle conjugate;   wherein the detection area comprises a chromatographic membrane and at least one analyte-conjugate protein, and   wherein the sample area is configured for receiving a liquid.   
     
     
         4 . The apparatus of  claim 2 , wherein the detection area further comprises at least one anti-species antibody or anti-species aptamer. 
     
     
         5 . The apparatus of  claim 2 , wherein the sample area, conjugate area, and the detection area are located on a single pad. 
     
     
         6 . The apparatus of  claim 2 , wherein at least one of the sample area, conjugate area, and the detection area is located on a separate pad. 
     
     
         7 . The apparatus of  claim 3 , wherein the chromatographic membrane comprises one or more of cellulose, nitrocellulose, polyester fiber, and/or glass fiber. 
     
     
         8 . The apparatus of  claim 2 , wherein the apparatus further comprises a cover defining a pattern, wherein the cover is disposed over the detection area. 
     
     
         9 . The apparatus of  claim 2 , wherein the detection area is positioned on or within or under a natural fingernail, an artificial fingernail, a layer of fingernail polish, a fingernail sticker, a fingernail decal, a sticker, a cup, a drink coaster, a drink stirrer, a toothpick, a drink ornament, a pencil, or a pen. 
     
     
         10 . The apparatus of  claim 2 , wherein the residual buffer composition comprises at least one surfactant. 
     
     
         11 . The apparatus of  claim 10 , wherein the surfactant comprises a poloxamer, a fatty alcohol, a polyethylene glycol alkyl ether, a polypropylene glycol alkyl ether, a glucoside alkyl ether, polyethylene glycol octyl, a glycerol alkyl ester, a phenyl ether, polyoxyethylene (20) oleyl ether, octylphenol ethoxylate, a polyethylene glycol alkylphenyl ether, polyethoxylated tallow amine, N,N-bis[3-(D-gluconamido)propyl]cholamide, polyoxyethylene (20) cetyl ether, dimethyldecylphosphine oxide, branched octylphenoxy poly(ethyleneoxy)ethanol, a polyoxyethylene-polyoxypropylene block copolymer, t-octylphenoxypolyethoxyethanol, polyoxyethylene (20) sorbitan monooleate, or a combination thereof. 
     
     
         12 . The apparatus of  claim 2 , wherein the residual buffer composition comprises at least one buffer salt. 
     
     
         13 . The apparatus of  claim 12 , wherein the buffer salt comprises monosodium phosphate, disodium phosphate, sodium tetraborate, Tris(hydroxymethyl)methylaminopropanesulfonic (TAPS), N-cyclohexyl-2-aminoethanesulfonic acid (CHES), N-tris(hydroxymethyl)methyl-4-aminobutanesulfonic acid (TABS), bis-tris methane (Bis TRIS), tris(hydroxymethyl)aminomethane (TRIS), 2-[[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonic acid (TES), 2-(N-morpholino)ethanesulfonic acid (YMS), N-(carbamoylmethyl)iminodiacetic acid (ADA), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), bis tris propane, piperazine-N,N′-bis(2-ethanesulfonic acid)(PIPES), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), 3-morpholino-2-hydroxypropanesulfonic acid (MOPSO), cholamine chloride, (3-(N-morpholino)propanesulfonic acid) (MOPS), N,N-bis(2-hydroxyethyl)taurine (BES), N,N-bis(2-hydroxyethyl)-3-amino-2-hydroxypropanesulfonic acid (DIPSO), 4-(N-morpholino)butanesulfonic acid (MOBS), 3-[N-rris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic acid (TAPSO), acetamidoglycine, triethanolamine (TEA), piperazine-N,N′-bis(2-hydroxypropanesulfonic acid) POPSO, 4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropanesulfonic acid) hydrate (HEPPSO), 3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid (HEPPS), tricine, tris(hydroxymethyl)aminomethane, trometamol (TRIZMA), glycinamide, glycyl-glycine, N-(2-hydroxyethyl)piperazine-N′-(4-butanesulfonic acid) (HEPBS), bicine, 2-amino-2-methyl-1-propanol (AMP), N-(1,1-dimethyl-2-hydroxyethyl)-3-amino-2-hydroxypropanesulfonic acid (AMPSO), N-cyclohexyl-2-hydroxyl-3-aminopropanesulfonic acid (CAPSO), N-cyclohexyl-3-aminopropanesulfonic acid (CAPS), 4-(cyclohexylamino)-1-butanesulfonic acid (CABS), and (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (HEPES), carnitine, gamma-aminobutyric acid, taurine, or salts of amino acids alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, or a combination thereof. 
     
     
         14 . The apparatus of  claim 2 , wherein the sample area comprises a residual sample area buffer composition, and wherein the residual sample area buffer composition comprises a potassium salt of a weak acid and at least one surfactant. 
     
     
         15 . The apparatus of  claim 2 , wherein the conjugate area comprises a residual conjugate area buffer composition, and wherein the residual conjugate area buffer composition comprises a Good's buffer salt and one or more of a protein, an oligomer, a polymer, and a surfactant. 
     
     
         16 . The apparatus of  claim 2 , wherein the detection area comprises a residual detection area buffer composition, and wherein the residual detection area buffer composition comprises a phosphate salt and one or more of a saccharide, a protein, an oligomer, and a polymer. 
     
     
         17 . The apparatus of  claim 1 , wherein the lateral flow assay is configured to detect multiple analytes. 
     
     
         18 . The apparatus of  claim 2 , wherein the residual buffer composition is configured to reduce the acidity of a test liquid. 
     
     
         19 . The apparatus of  claim 2 , wherein the residual buffer composition is configured to increase the viscosity of a test liquid. 
     
     
         20 . The apparatus of  claim 2 , wherein the residual buffer composition is configured to substantially reduce or substantially remove the appearance of colored components of a test liquid. 
     
     
         21 . A method of detecting an analyte in a liquid, said method comprising:
 providing the apparatus of  claim 1 ;   exposing a portion of the apparatus to the liquid; and   observing an indication to determine presence or absence of the analyte in the liquid.   
     
     
         22 . The method of  claim 21 , wherein the liquid is a beverage. 
     
     
         23 . The method of  claim 21 , wherein the liquid is a food extract. 
     
     
         24 . The method of  claim 21 , wherein the liquid has a pH from about 4.5 to about 6.8. 
     
     
         25 . A method of making an apparatus for detecting the presence of an analyte in a liquid, the method comprising:
 applying a buffer solution to at least one of
 a conjugate area; 
 a detection area; or 
 a sample area for receiving a liquid; 
   drying the buffer solution;   applying at least one anti-analyte antibody-particle conjugate or anti-analyte aptamer-particle conjugate to at least a portion of the conjugate area;   applying at least one analyte-conjugate protein to at least a portion of the detection area; and   assembling the conjugate pad, detection area, sample area and a wick so that the sample area is in contact with a portion of the conjugate area, another portion of the conjugate area is in contact with a proximal end of the detection area, and the wick is in contact with a distal end of the detection area.