Reduction of interference signal of ascorbate and urate in poly(pyrrole)-based ammonia sensors in aqueous solutions

Abstract The present paper outlines the methods used to reduce the interference signal caused by ascorbic and uric acids on an ammonia amperometric sensor in aqueous solutions. The sensor was prepared by electrochemical deposition of poly(pyrrole), doped with dodecylbenzenesulfonic anions (DBS), onto platinum substrates. Poly(pyrrole) films were coated with different membranes, aiming to find different ways to diminish the interference response of anionic species such as ascorbate and urate. Nafion ® , cellulose acetate and poly(5-amino-1-naphthol), were studied as permselective layers. This last polymer is electroactive, offering the possibility of its formation by electrochemical deposition onto poly(pyrrole). In order to verify the stability of poly(5-amino-1-naphthol) when used in basic medium, Raman spectra were taken from these modified electrodes. Further, all sensors showed a linear response and a good sensitivity in a concentration range from 0 to 120 μmol L −1 which covers the ammonia concentration range typical of clinical samples (18–72 μmol L −1 ).

[1]  P. Lacaze,et al.  Electrochemical synthesis and study of poly(5-amino 1-naphthol) film in aqueous and organic media , 1994 .

[2]  Luigi Campanella,et al.  Amperometric sensing of ammonia in aqueous solutions using a polyaniline‐modified electrode in flow injection systems , 1997 .

[3]  A. Ivaska,et al.  Interferences in a polypyrrole-based amperometric ammonia sensor. , 2000, Talanta.

[4]  J. Wang,et al.  Thin-layer electrochemical detector with a glassy carbon electrode coated with a base-hydrolyzed cellulosic film. , 1985, Analytical chemistry.

[5]  S. D. Torresi,et al.  Resonant Raman spectroscopy as a tool for determining the formation of a ladder structure in electropolymerized poly(5-amino-1-naphthol) , 2002 .

[6]  Göran Gustafsson,et al.  The interaction between ammonia and poly(pyrrole) , 1989 .

[7]  A. Lewenstam,et al.  Flow injection amperometric detection of ammonia using a polypyrrole‐modified electrode and its application in urea and creatinine biosensors , 1996 .

[8]  S. D. Torresi,et al.  Electronic and ionic exchange in poly(5-amino 1-naphthol) in acid aqueous solution , 2004 .

[9]  N. Oyama,et al.  Formation of a novel electroactive film by electropolymerization of 5-amino-1-naphthol , 1991 .

[10]  Subhas Chandra,et al.  Application of conducting polyaniline as sensor material for ammonia , 1997 .

[11]  Susumu Kuwabata,et al.  EQCM studies on polypyrrole in aqueous solutions , 1997 .

[12]  Alexander M. Yacynych,et al.  Electropolymerized 1,2-diaminobenzene as a means to prevent interferences and fouling and to stabilize immobilized enzyme in electrochemical biosensors , 1990 .

[13]  C. Barbero,et al.  Ion Exchange in Poly(5‐amino‐1‐naphthol) Probe Beam Deflection and Multiple Internal Reflection Fourier Transform Infrared Spectroscopic Studies , 1995 .

[14]  Joseph Wang,et al.  Flow injection analysis as a tool for studying polymer modified electrodes , 1996 .

[15]  S. D. Torresi,et al.  "On line" mass spectrometric detection of ammonia oxidation products generated by polypyrrole based amperometric sensors , 2003 .

[16]  Sergey A. Piletsky,et al.  Ammonia sensors based on sensitive polyaniline films , 1996 .

[17]  S. D. Torresi,et al.  A New Sensor for Ammonia Determination Based on Polypyrrole Films Doped with Dodecylbenzenesulfonate (DBSA) Ions , 2002 .

[18]  C. Dejong,et al.  Interorgan ammonia metabolism in liver failure , 2002, Neurochemistry International.

[19]  A. Ivaska,et al.  A polypyrrole-based amperometric ammonia sensor. , 1996, Talanta.

[20]  B. I. Cohen.  The significance of ammonia/gamma-aminobutyric acid (GABA) ratio for normality and liver disorders. , 2002, Medical hypotheses.

[21]  L. Murphy.  Reduction of Interference Response at a Hydrogen Peroxide Detecting Electrode Using Electropolymerized Films of Substituted Naphthalenes , 1998 .