Electrosynthesis of nanofibers and nano-composite films

Abstract

A method for producing an array of oriented nanofibers that involves forming a solution that includes at least one electroactive species. An electrode substrate is brought into contact with the solution. A current density is applied to the electrode substrate that includes at least a first step of applying a first substantially constant current density for a first time period and a second step of applying a second substantially constant current density for a second time period. The first and second time periods are of sufficient duration to electrically deposit on the electrode substrate an array of oriented nanofibers produced from the electroactive species. Also disclosed are films that include arrays or networks of oriented nanofibers and a method for amperometrically detecting or measuring at least one analyte in a sample.

1 - 39 . (canceled)  
     
     
         40 . An array of oriented nanofibers produced by a method comprising: 
 forming a solution that includes at least one electroactive species;    contacting the solution and an electrode substrate; and    applying a current to the electrode substrate that includes at least a first step of applying a first substantially constant current density for a first time period and a second step of applying a second substantially constant current density for a second time period, wherein the first substantially constant current density is greater than the second substantially constant current density; and    wherein the first time period and second time period are of sufficient duration to electrically deposit on the electrode substrate an array of oriented nanofibers produced from the electroactive species.    
     
     
         41 . A substrate defining at least one surface having deposited thereon an array of freestanding oriented organic polymer nanofibers, wherein the array was produced by liquid phase processing and without a template.  
     
     
         42 . The substrate of  claim 41 , wherein the organic polymer nanofibers comprise a conducting polymer.  
     
     
         43 . The substrate of  claim 42 , wherein the conducting polymer comprises a polyaniline, polythiophene, polypyrrole, polyarylene, polyphenylene, poly(bisthiophenephenylene), conjugated ladder polymer, poly(arylene vinylene), poly(arylene ethynylene), organometallic derivative thereof, or inorganic derivative thereof.  
     
     
         44 . The substrate of  claim 41 , wherein the oriented nanofibers are substantially unidirectionally oriented.  
     
     
         45 . The substrate of  claim 41 , wherein the oriented nanofibers are three-dimensionally oriented.  
     
     
         46 . The substrate of  claim 44 , wherein the unidirectionally oriented fibers are substantially perpendicular to a plane formed by the substrate surface.  
     
     
         47 . The substrate of  claim 41 , wherein the nanofibers have an average diameter of less than about  1  micron and an average length of about 500 to about 10,000 nm.  
     
     
         48 . A film comprising a network of three-dimensionally oriented conducting polymer nanofibers, wherein the individual nanofibers have a substantially uniform cylindrical shape and there is substantially no branching of the individual nanofibers.  
     
     
         49 . The film of  claim 48 , wherein the nanofiber network defines nanometer-sized voids and further comprises a second substance at least partially received within the nanometer-sized voids of the nanofiber network.  
     
     
         50 . The film of  claim 49 , wherein the second substance comprises a metallic material.  
     
     
         51 . The film of  claim 50 , wherein the second substance comprises a metal hexacyanometallate.  
     
     
         52 . The film of  claim 51 , wherein the metal hexacyanometallate comprises M 1 M 2 (III)[M 3 (II)(CN) 6 ] or M 2 (III) 4 [M 3 (II)(CN) 6 ] 3  wherein M 2 (III) is Fe(III), Ru(III), Os(III), or Co(III); M 3 (II) is Fe(II), Ru(II), Os(II), or Co(II); and M 1  is an alkali metal cation.  
     
     
         53 . The film of  claim 52 , wherein the metal hexacyanometallate comprises iron (III) hexacyanoferrate.  
     
     
         54 - 61 . (canceled)