Personal glucose meters for detection and quantification of a broad range of analytes

Abstract

A methodology for developing highly sensitive and selective sensors that can achieve portable, low-cost and quantitative detection of a broad range of targets using only a personal glucose meter (PGM) is disclosed. The method uses recognition molecules specific for a target agent, enzymes that can convert an enzyme substrate into glucose, and a PGM. Also provided are sensors, which can include a solid support having attached thereto a recognition molecule that permits detection of a target agent, as well as an enzyme that can catalyze the conversion of a substance into glucose, wherein the enzyme is attached directly or indirectly to the recognition molecule, and wherein in the presence of the target agent the enzyme can convert the substance into glucose. The disclosed sensors can be part of a lateral flow device. Methods of using such sensors for detecting target agents are provided.

1 . A sensor, comprising
 a solid support to which is attached a recognition molecule that permits detection of a target agent, wherein the recognition molecule specifically binds to the target agent in the presence of the target agent but not significantly to other agents; and   an enzyme that can catalyze the conversion of a substance into glucose, wherein the enzyme is attached directly or indirectly to the recognition molecule, and wherein in the presence of the target agent the enzyme can convert the substance into glucose.   
     
     
         2 . The sensor of  claim 1 , wherein the enzyme is attached to the recognition molecule directly. 
     
     
         3 . The sensor of  claim 1 , wherein the enzyme is attached to the recognition molecule indirectly, and the enzyme is part of an analyte-analogue conjugate that can bind to the recognition molecule, and wherein in the presence of the target agent the enzyme is released from the solid support and can then convert the substance into glucose 
     
     
         4 . The sensor of  claim 1 , wherein the enzyme is attached to the recognition molecule indirectly, and the enzyme is part of an analyte-analogue conjugate that can bind to the target agent bound to the recognition molecule, and wherein in the presence of the target agent the enzyme can convert the substance into glucose. 
     
     
         5 . The sensor of  claim 1 , wherein the solid support comprises a bead or a membrane. 
     
     
         6 . The sensor of  claim 1 , wherein the solid support comprises glass or nitrocellulose. 
     
     
         7 . The sensor of  claim 1 , wherein the recognition molecule comprises a nucleic acid molecule, protein, polymer, or an antibody that specifically binds to the target agent. 
     
     
         8 . The sensor of  claim 7 , wherein the nucleic acid molecule comprises DNA, RNA, peptide nucleic acid (PNA), or locked nucleic acid (LNA). 
     
     
         9 . The sensor of  claim 7 , wherein the nucleic acid molecule comprises a functional nucleic acid. 
     
     
         10 . The sensor of  claim 1 , wherein the target agent comprises a metal, microbe, cytokine, hormone, cell, nucleic acid molecule, spore, protein, recreational drug, or toxin. 
     
     
         11 . The sensor of  claim 1 , wherein the enzyme is:
 an invertase, sucrase, or sucrase-isomaltase that can convert sucrose into glucose,   a maltase that can convert maltose into glucose,   a trehalase that can convert trehalose into glucose,   an amylase that can convert starch into glucose, or   a cellulase that can convert cellulose into glucose.   
     
     
         12 . A lateral flow device comprising:
 the sensor of  claim 1 .   
     
     
         13 . The lateral flow device of  claim 12 , wherein the lateral flow device comprises:
 a sample or wicking pad;   a conjugation pad, wherein the sensor is conjugated to the conjugation pad;   a membrane comprising the substance that can be converted into glucose; and   an absorption pad.   
     
     
         14 . The lateral flow device of  claim 13 , wherein the sensor comprises a DNA aptamer-invertase or an antibody-invertase conjugate, wherein the DNA aptamer or antibody are specific for a target agent, and wherein the substance that can be converted into glucose is sucrose. 
     
     
         15 . The lateral flow device of  claim 14 , wherein the target agent is a metal, microbial antigen, spore, or microbial nucleic acid sequence. 
     
     
         16 . A kit comprising:
 one or more sensors of  claim 1 ; and   one or more of a buffer, a chart for correlating detected glucose level and amount of target agent present, or the substance that the enzyme can convert into glucose.   
     
     
         17 . The kit of  claim 16 , wherein the substance that the enzyme can convert into glucose comprises sucrose, maltose, trehalose, cellulose, or starch. 
     
     
         18 . A method for detecting a target agent, comprising
 contacting one or more sensors of  claim 1  with a sample under conditions sufficient to allow the target agent in the sample to release the enzyme from the solid support;   separating the solid support from the released enzyme;   contacting the released enzyme with the substance that the enzyme can convert into glucose, thereby generating glucose; and   detecting glucose, wherein detection of glucose indicates the presence of the target agent in the sample, and an absence of detected glucose indicates the absence of the target agent in the sample.   
     
     
         19 . A method for detecting a target agent, comprising
 contacting one or more sensors of  claim 1  with a sample under conditions sufficient to allow the target agent in the sample to bind to the recognition molecule, thereby creating a target agent-recognition molecule complex;   contacting the target agent-recognition molecule complex with an enzyme, wherein the enzyme is conjugated to a second recognition molecule, thereby creating a target agent-recognition molecule-enzyme recognition molecule complex;   contacting the enzyme with the substance that the enzyme can convert into glucose, thereby generating glucose; and   detecting glucose, wherein detection of glucose indicates the presence of the target agent in the sample, and an absence of detected glucose indicates the absence of the target agent in the sample.   
     
     
         20 . The method of  claim 19 , wherein the recognition molecule and the second recognition molecule are different molecules, but both specifically bind to the target agent. 
     
     
         21 . A method for detecting a target agent, comprising
 contacting one or more lateral flow devices of  claim 12  with a sample under conditions sufficient to allow the target agent in the sample to flow through the lateral flow device and bind to the recognition molecule present on the lateral flow device;   forming a target agent-recognition molecule complex, wherein formation of the target agent-recognition molecule complex results in the release of the enzyme that can convert the substance into glucose;   allowing the enzyme to interact with the substance that the enzyme can convert into glucose, thereby generating glucose; and   detecting glucose, wherein detection of glucose indicates the presence of the target agent in the sample, and an absence of detected glucose indicates the absence of the target agent in the sample.   
     
     
         22 . The method of  claim 18 , further comprising quantifying the target agent, wherein a level of glucose detected indicates an amount of target agent present. 
     
     
         23 . The method of  claim 12 , wherein
 the enzyme comprises invertase, sucrase, or sucrase-isomaltase and the substance that the enzyme can convert into glucose comprises sucrose, or   the enzyme comprises maltase and the substance that the enzyme can convert into glucose comprises maltose, or   the enzyme comprises trehalase and the substance that the enzyme can convert into glucose comprises trehalose, or   the enzyme comprises cellulase and the substance that the enzyme can convert into glucose comprises cellulose, or   the enzyme comprises amylase and the substance that the enzyme can convert into glucose comprises starch.   
     
     
         24 . The method of  claim 18 , wherein the glucose is detected using a personal glucose meter. 
     
     
         25 . The method of  claim 28 , wherein the target agent comprises a metal, microbe, cytokine, hormone, cell, nucleic acid molecule, spore, protein, recreational drug, or toxin. 
     
     
         26 . A sensor, comprising
 a solid support to which is attached a recognition molecule specifically binds to the target agent in the presence of the target agent but not significantly to other agents; and   an enzyme-target complex, wherein the enzyme can catalyze the conversion of a substance into glucose, wherein the enzyme is attached directly or indirectly to the target agent, and wherein in the presence of the target agent in the sample the amount of enzyme-target agent complex bound to the solid support decreases, and wherein the amount of target in the sample is proportional to the amount of unbound enzyme-target agent complexes.   
     
     
         27 . A method for detecting a target agent, comprising
 contacting one or more sensors of  claim 26  with a sample and with the enzyme-target complex under conditions sufficient to allow the target agent in the sample to compete with the enzyme-target complex for binding to the recognition molecule on the solid support;   separating the solid support from unbound target and unbound enzyme-target complex;   contacting the unbound enzyme-target complex with the substance that the enzyme can convert into glucose, thereby generating glucose; and   detecting glucose, wherein detection of glucose indicates the presence of the target agent in the sample, and an absence of detected glucose indicates the absence of the target agent in the sample.   
     
     
         28 . A sensor, comprising
 a solid support to which is attached a recognition molecule specifically binds to the target agent in the presence of the target agent but not significantly to other agents;   a target conjugated to a first molecule; and   an enzyme conjugated to a second molecule, wherein the enzyme can catalyze the conversion of a substance into glucose, wherein the first and second molecule are complementary and can form an indirect enzyme-target complex, and wherein in the presence of the target agent in the sample the amount of indirect enzyme-target agent complex bound to the solid support decreases, and wherein the amount of target in the sample is inversely proportional to the amount of unbound enzyme-target agent complex.   
     
     
         29 . A method for detecting a target agent, comprising
 contacting one or more sensors of  claim 28  with a sample under conditions sufficient to allow the target agent in the sample to compete with the target conjugated to the first molecule for binding to the recognition molecule on the solid support;   contacting the solid support with the enzyme conjugated to a second molecule, under conditions where in the first and second molecule hybridize to one another;   contacting the solid support with the substance that the enzyme can convert into glucose, thereby generating glucose; and   detecting glucose, wherein the detected glucose is inversely proportional to the amount of the target agent in the sample.   
     
     
         30 . A microfluidic device comprising:
 the sensor of  claim 1 .