Voltammetric sensor array based on conducting polymer-modified electrodes for the discrimination of liquids

Abstract In this work, a novel type of voltammetric electrodes based on conducting polymers has been developed and used as sensing units of a sensory system. Polymeric sensors have been obtained by electrodeposition of the corresponding monomers (3-methylthiophene, aniline and pyrrole) onto platinum disks using a range of doping agents. The electrochemical response of polypyrrole electrodes is particularly rich and stable. Moreover, their electrochemical characteristics can be improved by using large anions or redox anions as dopants. A multichannel liquid sensor has been constructed using those sensors showing the best performances in terms of stability and variety of responses. The array of sensors has been exposed to solutions with distinct taste properties (sweet, bitter, acid, salty and astringent). Each sensor shows a characteristic electrochemical response when exposed to the studied solutions, providing a high degree of cross-selectivity. The principal component analysis (PCA) of the obtained signals has allowed the discrimination of the solutions tested.

[1]  Li Yongfang,et al.  On the nature of redox processes in the cyclic voltammetry of polypyrrole nitrate in aqueous solutions , 1993 .

[2]  Fredrik Winquist,et al.  Investigation of Electrode Materials as Sensors in a Voltammetric Electronic Tongue , 2002 .

[3]  Shaoan Cheng,et al.  Electrogeneration and electrochemical properties of hybrid materials: polypyrrole doped with polyoxometalates PW12−xMoxO403− (x=0,3,6,12) , 2002 .

[4]  A. MacDiarmid,et al.  "Synthetic Metals": A Novel Role for Organic Polymers (Nobel Lecture). , 2001, Angewandte Chemie.

[5]  Fernando J. Fonseca,et al.  Artificial Taste Sensor: Efficient Combination of Sensors Made from Langmuir−Blodgett Films of Conducting Polymers and a Ruthenium Complex and Self-Assembled Films of an Azobenzene-Containing Polymer , 2002 .

[6]  Kenshi Hayashi,et al.  Comparison of a voltammetric electronic tongue and a lipid membrane taste sensor , 2001 .

[7]  J. Lukkari,et al.  Redox processes in thick films of polypyrrole/dodecylsulfate in the presence of alkali and tetramethylammonium chlorides , 1995 .

[8]  A. Öpik,et al.  Ion transport investigations of polypyrroles doped with different anions by EQCM and CER techniques , 2003 .

[9]  R. L. Elsenbaumer,et al.  Handbook of conducting polymers , 1986 .

[10]  Pierre Gros,et al.  Use of polypyrrole film containing Fe(CN)63− as pseudo-reference electrode: application for amperometric biosensors , 2001 .

[11]  G. Wallace,et al.  The Use of Chronoamperometry and Chemometrics for Optimization of Conducting Polymer Sensor Arrays , 1999 .

[12]  I. Lundström,et al.  Flow injection analysis applied to a voltammetric electronic tongue , 2002 .

[13]  H. Lüth,et al.  Development of multisensor systems based on chalcogenide thin film chemical sensors for the simultaneous multicomponent analysis of metal ions in complex solutions , 2001 .

[14]  Väino Sammelselg,et al.  Electrochemical properties of polypyrrole/sulphate films , 1997 .

[15]  Alisa Rudnitskaya,et al.  Electronic Tongues: Sensors, Systems, Applications , 2002 .

[16]  Ricardo Gutierrez-Osuna,et al.  A method for evaluating data-preprocessing techniques for odour classification with an array of gas sensors , 1999, IEEE Trans. Syst. Man Cybern. Part B.

[17]  Guo-Li Shen,et al.  Potentiometric sensors: aspects of the recent development☆ , 2000 .

[18]  Andrew D. Ellington,et al.  Solution-based analysis of multiple analytes by a sensor array: toward the development of an electronic tongue , 1998 .

[19]  M. Paoli,et al.  Effect of the electrolyte cations and anions on the photocurrent of dodecylsulphate doped polypyrrole films , 2002 .

[20]  Ingemar Lundström,et al.  The combination of an electronic tongue and an electronic nose , 1999 .

[21]  V. N. Krishnamurthy,et al.  Oligomeric metallo phthalocyanine-incorporated conducting polymers , 2000 .

[22]  Maria Luz Rodriguez-Mendez,et al.  Langmuir–Blodgett film and carbon paste electrodes based on phthalocyanines as sensing units for taste , 2003 .