Self-actuating signal producing detection devices and methods

Abstract

An assay system is provided of great sensitivity and portability where the presence of a specific target in a sample, as well as its concentration (qualification and quantification) is detected by reason of a potential or voltage in a closed circuit, built up a redox reaction. The reaction is produced by binding a capture moiety to an enzymatic redox reaction partner, allowing the capture moiety to bind to any target in the sample, and washing any such bound target. The bound target, if not immobilized, may be immobilized through use of a second capture moiety. Substrate for the enzyme is then added. The action of the enzyme upon the substrate frees electrons, creating a potential across an anode and cathode which may be separated by a membrane.

1 - 31 . (canceled) 
     
     
         32 . An assay system for detecting a target in a liquid sample in the field, wherein said system comprises:
 A plurality of capture moieties which bind to any said target in said sample, said capture moieties each comprising an antibody conjugated with glucose oxidase,   A plurality of detection moieties which bind to any target in said sample simultaneously with binding of said capture moieties to said target, said detection moieties each comprising a second antibody conjugated to a magnetic bead, and   A reaction chamber to which said sample and any capture moieties and detection moieties bound thereto are combined following washing with glucose, horseradish peroxidase and an electron mediator such that digestion of glucose by said glucose oxidase generates hydrogen peroxide which is oxidized by said horseradish peroxidase releasing electrons to said electron mediator, which electrons are directly detected by said system, wherein the detection of said electrons indicates the presence of said target in said sample.   
     
     
         33 . The system of  claim 32 , wherein said target is a virus, spore or bacteria. 
     
     
         34 . The system of  claim 32  where no voltage other than the electrons released by said electron mediator is supplied to said system to detect presence of said target in said sample. 
     
     
         35 . The system of  claim 32 , wherein said electron mediator is 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate). 
     
     
         36 . The system of  claim 32 , wherein the binding of capture moieties and detection moieties generates a colorimetric signal. 
     
     
         37 . A handheld self-powered field deployable detector for detection of a target in a liquid sample, wherein said detector comprises a reaction chamber wherein said sample is combined with 1) a plurality of capture moieties which bind to any target in said sample, said capture moieties each comprising an antibody conjugated with glucose oxidase, 2) a plurality of detection moieties which bind to any target in said sample simultaneously with binding of said capture moieties to said target, said detection moieties each comprising a second antibody conjugated to a magnetic bead, and wherein following washing of said sample and said capture and detection moieties, glucose, horseradish peroxidase and an electron mediator are added to said reaction chamber, whereby said detector detects the presence of any target in said sample by detecting release of electrons from said electron mediator which receives electrons from any hydrogen peroxide generated by digestion of said glucose which hydrogen peroxide is then oxidized by aid horseradish peroxidase. 
     
     
         38 . The detector of  claim 37 , wherein said target is a virus, spore or bacteria. 
     
     
         39 . The detector of  claim 37 , wherein said mediator is 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate). 
     
     
         40 . The detector of  claim 37 , wherein said electrons are detected without the input of additional voltage to said detector other than that generated by electrons captured by said electron mediator. 
     
     
         41 . A method for the detection of a target in a sample, comprising:
 Suspending said sample in a liquid medium;   Combining said sample in said liquid medium with A) a plurality of capture moieties which bind to any target in said sample, said capture moieties each comprising an antibody conjugated with glucose oxidase, and B) a plurality of detection moieties which bind to any target in said sample simultaneously with binding of said capture moieties to said target, said detection moieties each comprising a second antibody conjugated to a magnetic bead;   Washing said sample to remove unbound sample material therefrom;   Adding glucose, horseradish peroxidase and an electron mediator to said washed sample, such that any hydrogen peroxide generated by digestion of said glucose is caused to release electrons to said electron mediator; and   Detecting said electrons released to said electron mediator.   
     
     
         42 . The method of  claim 41 , wherein said electrons are detected without the input of additional voltage to said detector other than that generated by electrons captured by said electron mediator 
     
     
         43 . The method of  claim 41 , wherein said electron mediator is 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate).