Methods for detecting an amount of an analyte in a solution

Abstract

A method for detecting an amount of an analyte in a solution includes adding an electrochemically active agent to the solution; applying an electrical current to a working electrode in contact with the solution to initiate the electrochemical redox reaction to change a pH of the solution from a first pH value to a second pH value; incubating the solution at the second pH value to allow the analyte to dissociate from the other molecules in the solution and to bind to a capture molecule connected to the working electrode via a linker; reacting a detecting probe with the analyte to allow the detecting probe to bind to the analyte, the detecting probe having a signaling tag attached thereto and configured to produce a signal at the second pH value; and collecting the signal to calculate the amount of the analyte in the solution.

What is claimed is: 
     
         1 . A method for detecting an amount of an analyte in a solution, the method comprising:
 adding an electrochemically active agent to the solution containing molecules other than the electrochemically active agent, the electrochemically active agent generating or consuming hydrogen (H + ) ions in the solution through an electrochemical redox reaction;   applying an electrical current to a working electrode in contact with the solution containing the electrochemically active agent to initiate the electrochemical redox reaction to change a pH of the solution from a first pH value to a second pH value, the second pH value being different from the first pH value;   incubating the solution at the second pH value to allow the analyte to dissociate from the other molecules in the solution;   reacting the analyte with a detecting probe to bind the analyte to the detecting probe, the detecting probe having a signaling tag attached thereto and configured to produce a signal at the second pH value; and   collecting the signal to calculate the amount of the analyte in the solution.   
     
     
         2 . The method of  claim 1 , wherein the incubating step further includes incubating the solution at the second pH value to allow the analyte to bind to a capture molecule connected to the working electrode via a linker. 
     
     
         3 . The method of  claim 2 , wherein the analyte is an anti-drug antibody (ADA). 
     
     
         4 . The method of  claim 2 , wherein the electrochemically active agent is selected from the group consisting of quinone, catechol, aminophenol, hydrazine, hydroquinone, benzoquinone, naphthoquinone, derivatives thereof, and combinations thereof. 
     
     
         5 . The method of  claim 2 , wherein the signaling tag is selected from the group consisting of a fluorescent tag, a fluorescent dye, a fluorescent protein, an electroluminescent dye, a chemiluminescent dye, and an enzyme. 
     
     
         6 . The method of  claim 2 , wherein the linker is a polymeric material configured to immobilize the capture molecule through adsorption. 
     
     
         7 . The method of  claim 2 , wherein the linker is a protein configured to immobilize the capture molecule through affinity. 
     
     
         8 . The method of  claim 2 , wherein the linker is a polynucleic acid configured to immobilize the capture molecule through hybridization. 
     
     
         9 . The method of  claim 2 , wherein the linker is an organic molecule configured to immobilize the capture molecule through covalent binding. 
     
     
         10 . A method for detecting an amount of an analyte in a solution, the method comprising:
 adding an electrochemically active agent to the solution containing molecules other than the electrochemically active agent, the electrochemically active agent generating or consuming hydrogen (H + ) ions in the solution through an electrochemical redox reaction;   applying a first electrical current to a working electrode in contact with the solution containing the electrochemically active agent to initiate a first electrochemical redox reaction to change a pH of the solution from a first pH value to a second pH value, the second pH value being different from the first pH value;   incubating the solution at the second pH value to allow the analyte to dissociate from the other molecules in the solution;   applying a second electrical current to the working electrode to initiate a second electrochemical redox reaction to change the pH of the solution from the second pH value to a third pH value, the third pH value being different from the second pH value;   incubating the solution at the third pH value to allow the analyte to bind to a capture molecule connected to the working electrode via a linker;   reacting a detecting probe with the analyte to allow the detecting probe to bind to the analyte, the detecting probe having a signaling tag attached thereto and configured to produce a signal at the third pH value; and   collecting the signal to calculate the amount of the analyte in the solution.   
     
     
         11 . The method of  claim 10 , wherein the analyte is an anti-drug antibody (ADA). 
     
     
         12 . The method of  claim 10 , wherein the electrochemically active agent is selected from the group consisting of quinone, catechol, aminophenol, hydrazine, hydroquinone, benzoquinone, naphthoquinone, derivatives thereof, and combinations thereof. 
     
     
         13 . The method of  claim 10 , wherein the second pH value is lower than the first pH value. 
     
     
         14 . The method of  claim 10 , wherein the second pH value is lower than the third pH value. 
     
     
         15 . The method of  claim 10 , wherein the signaling tag is selected from the group consisting of a fluorescent tag, a fluorescent dye, a fluorescent protein, an electroluminescent dye, a chemiluminescent dye, and an enzyme. 
     
     
         16 . A method for detecting an amount of an analyte in a solution with a first pH value, the method comprising:
 adding a detecting probe to the solution, the detecting probe having a signaling tag attached thereto and configured not to produce a signal at the first pH value;   adding an electrochemically active agent to the solution containing molecules other than the electrochemically active agent and the detecting probe, the electrochemically active agent generating or consuming hydrogen (H + ) ions in the solution through an electrochemical redox reaction;   applying a first electrical current to a working electrode in contact with the solution to initiate a first redox reaction to change a pH of the solution from the first pH value to a second pH value, the second pH value being different from the first pH value;   incubating the solution at the second pH value to allow the analyte to dissociate from the other molecules in the solution and to bind to a capture molecule connected to the working electrode via a linker and to the detecting probe, the signaling tag attached to the detecting probe being configured to produce a first signal at the second pH value; and   collecting the first signal to calculate a first amount of the analyte in the solution.   
     
     
         17 . The method of  claim 16 , further comprising:
 applying a second electrical current to the working electrode in contact with the solution to initiate a second redox reaction to change the pH of the solution from the second pH value to a third pH value, the third pH value being different from the second pH value;   incubating the solution at the third pH value, the signaling tag being configured to produce a second signal at the third pH value, the second signal being stronger than the first signal; and   collecting the second signal to calculate a second amount of the analyte in the solution, the second amount being higher than the first amount.   
     
     
         18 . The method of  claim 16 , wherein the analyte is an anti-drug antibody (ADA). 
     
     
         19 . The method of  claim 16 , wherein the electrochemically active agent is selected from the group consisting of quinone, catechol, aminophenol, hydrazine, hydroquinone, benzoquinone, naphthoquinone, derivatives thereof, and combinations thereof. 
     
     
         20 . The method of  claim 16 , wherein the signaling tag is selected from the group consisting of a fluorescent tag, a fluorescent dye, a fluorescent protein, an electroluminescent dye, a chemiluminescent dye, and an enzyme.