Tissue-penetrating electrochemical sensor featuring a co-electrodeposited thin film comprised of polymer and bio-recognition element

Abstract

A method and device to impart the ability to selectively quantify chemical/biochemical analytes occupying physiological fluids via an automated process that allow the precise and spatially-defined simultaneous deposition of a thin-film of polymer containing an immobilized biorecognition element dispersed therein. A tissue penetrating electrochemical sensor comprises at least one working electrode and at least one of a reference electrode and a counter electrode.

1 - 20 . (canceled) 
     
     
         21 . A method of fabricating a tissue-penetrating electrochemical sensor for quantification of a chemical entity or a biochemical entity in a physiological fluid, the method comprising:
 applying a conducting polymer film to a surface of a working electrode, the application comprising:
 immersing an array of microelectrodes in a solution comprising a biorecognition element and a monomer precursor, the array of microelectrodes comprising the working electrode; and 
 applying, during the immersion of the array of microelectrodes in the solution, a potential at the working electrode, the application of the potential resulting in an electrodeposition of the conducting polymer film on the surface of the working electrode. 
   
     
     
         22 . The method of  claim 21 , wherein the conducting polymer film is synthesized from the monomer precursor. 
     
     
         23 . The method of  claim 22 , wherein the biorecognition element is entrapped and dispersed uniformly in the conducting polymer film. 
     
     
         24 . The method of  claim 21 , wherein the monomer precursor is dissolved in the solution. 
     
     
         25 . The method of  claim 21 , wherein the electrodeposition of the conducting polymer film comprises a co-electrodeposition of the biorecognition element and the monomer precursor. 
     
     
         26 . The method of  claim 21 , wherein the biorecognition element comprises at least one of an enzyme, a biocatalyst, an inorganic catalyst, an ion-selective material, an antibody, aptamer, an oligonucleotide, an electrochemical redox mediator, a cell, and an organelle. 
     
     
         27 . The method of  claim 21 , wherein the monomer precursor comprises an organic monomer. 
     
     
         28 . The method of  claim 21 , wherein the potential comprises a fixed potential or a time-varying potential. 
     
     
         29 . The method of  claim 28 , wherein the potential is selected to result in a thickness of the conducting polymer film ranging from about 5 to about 5,000 nanometers. 
     
     
         30 . The method of  claim 21 , wherein the potential is applied for a specified time duration to result in a thickness of the conducting polymer film ranging from about 5 to about 5,000 nanometers. 
     
     
         31 . The method of  claim 21 , wherein the potential is selected to pass a specified amount of charge through the working electrode to result in a thickness of the conducting polymer film ranging from about 5 to about 5,000 nanometers. 
     
     
         32 . The method of  claim 21 , wherein the array of microelectrodes further comprises another electrode, wherein the application of the potential comprises applying the potential between the working electrode and the other electrode. 
     
     
         33 . The method of  claim 32 , wherein the other electrode comprises a counter electrode or a reference electrode. 
     
     
         34 . The method of  claim 21 , wherein the array of microelectrodes further comprises a counter electrode and a reference electrode, wherein the application of the potential comprises applying the potential between the working electrode and at least one of the counter electrode and the reference electrode. 
     
     
         35 . The method of  claim 21 , wherein the array of microelectrodes comprises a plurality of working electrodes, wherein the application of the potential comprises applying the potential at each of the plurality of working electrodes, the application of the potential resulting in the electrodeposition of the conducting polymer film on a respective surface of each of the plurality of working electrodes. 
     
     
         36 . A method of fabricating a tissue-penetrating electrochemical sensor for quantification of a chemical entity or a biochemical entity in a physiological fluid, the method comprising:
 applying a conducting polymer film to a respective surface of each of a plurality of working electrodes, the application comprising:
 immersing an array of microelectrodes in a solution comprising a biorecognition element and a monomer precursor, the array of microelectrodes comprising the plurality of working electrodes; and 
 applying, during the immersion of the array of microelectrodes in the solution, a potential at the plurality of working electrodes, the application of the potential resulting in an electrodeposition of the conducting polymer film on the respective surface of each of the plurality of working electrodes. 
   
     
     
         37 . A tissue-penetrating electrochemical sensor device for quantification of a chemical entity or a biochemical entity in a physiological fluid, the device comprising:
 an array of microelectrodes comprising a plurality of working electrodes; and   a conducting polymer film on a respective surface of each of the plurality of working electrodes, the conducting polymer film comprising a monomer precursor and a biorecognition element, the conducting polymer film electrodeposited on the respective surface of each of the plurality of working electrodes in response to immersion of the plurality of working electrodes in a solution and application of a potential applied to each of the plurality of working electrodes, the solution comprising the biorecognition element and the monomer precursor.   
     
     
         38 . The device of  claim 37 , wherein the conducting polymer film has a thickness of about 1 to about 100 nanometers. 
     
     
         39 . The device of  claim 37 , wherein the conducting polymer film is synthesized from the monomer precursor, wherein the biorecognition element is entrapped and dispersed uniformly in the conducting polymer film, and wherein the monomer precursor is dissolved in the solution. 
     
     
         40 . The device of  claim 37 , wherein the potential applied to each of the plurality of working electrodes ranges from −0.5 volts to 1.5 volts.