Electrochemical sensors

Abstract

Systems and methods are provided for detecting the presence of an analyte in a sample. A solid state electrochemical sensor can include a redox active moiety having an oxidation and/or reduction potential that is sensitive to the presence of an analyte immobilized over a surface of a working electrode. A redox active moiety having an oxidation and/or reduction potential that is insensitive to the presence of the analyte can be used for reference. Voltammetric measurements made using such systems can accurately determine the presence and/or concentration of the analyte in the sample. The solid state electrochemical sensor can be robust and not require calibration or re-calibration.

What is claimed is: 
     
         1 . An analyte sensor, comprising:
 a first solid state working electrode having disposed thereon a redox-active moiety exhibiting an oxidation potential and/or a reduction potential that is sensitive to the presence of an analyte, said first solid state working electrode doped p-type; and   a second solid state working electrode having disposed thereon a redox-active moiety exhibiting an oxidation potential and/or a reduction potential that is insensitive to the presence of said analyte, said second solid state working electrode doped n-type or p-type.   
     
     
         2 . The analyte sensor of  claim 1 , wherein said first solid state working electrode has a resistivity that is greater than or equal to about 1 Ω-cm. 
     
     
         3 . The analyte sensor of  claim 1 , wherein said second solid state working electrode has a resistivity that is greater than or equal to about 5 μΩ-cm. 
     
     
         4 . The analyte sensor of  claim 1 , wherein said first and second solid state working electrodes are formed of a semiconductor. 
     
     
         5 . The analyte sensor of  claim 4 , wherein said semiconductor is silicon. 
     
     
         6 . The analyte sensor of  claim 4 , wherein said second solid state working electrode is doped n-type and has a resistivity that is greater than or equal to about 1 Ω-cm. 
     
     
         7 . The analyte sensor of  claim 6 , wherein the resistivity of the second solid state working electrode is between about 1 Ω-cm and 90 Ω-cm.