Conducting Polymer Based Electrochemical Sensors on Thick Film Substrate

New types of electroconducting conjugated polymer (ECP) based enzymatic and gas sensors were developed by using thick film technology. In order to prepare a stable polymeric film which is suitable for the enzyme immobilization and for gas detection itself, a special conducting salt (sodium dodecyl sulfate, SDS) was used. This combination resulted in sensors with favorable properties, i.e., higher sensitivity and longer operation stability. In the case of the ECP based uric acid biosensor a new layout was developed for the measurement of the current difference between the polymer and the enzyme electrode by using two working electrodes identically prepared (sensor and polymer electrodes) at the same time in the same solution. The sensor gives an easily measurable stationary response in the physiological concentration range of uric acid. Using a similar electropolymerization method, a selective ECP based sensor was prepared as part of a sensor array for intelligent gas monitoring. The changes in conductivity of the polypyrrole film in the presence of different gases were registered. A reversible sensor response of about 30 % in saturated methanol=air mixture and 50 % at 1000 ppm ammonia in air was obtained at room temperature. For NH3 a linear response in the 40‐1000 ppm concentration range could be registered while almost no response was obtained for ethanol, NO and CO. The sensor proved to be insensitive for H2.

[1]  Mu Shaolin,et al.  Effect of thiourea on the activity of the polypyrrole uricase electrode and determination of thiourea , 1993 .

[2]  G. Bidan,et al.  Electroconducting conjugated polymers: New sensitive matrices to build up chemical or electrochemical sensors. A review☆ , 1992 .

[3]  P. Bartlett,et al.  Conducting polymer gas sensors Part III: Results for four different polymers and five different vapours , 1989 .

[4]  P. Bartlett,et al.  Theoretical treatment of diffusion and kinetics in amperometric immobilized enzyme electrodes Part I: Redox mediator entrapped within the film , 1995 .

[5]  Ashton C. Partridge,et al.  Mechanistic studies on the interactions between poly(pyrrole) and organic vapors , 1993 .

[6]  Philip N. Bartlett,et al.  Conducting polymer gas sensors part II: response of polypyrrole to methanol vapour , 1989 .

[7]  Gÿbor Harsÿnyi,et al.  Polymer Films in Sensor Applications , 1995 .

[8]  A. L. Hart,et al.  Electrochemical oxidation of hydrogen peroxide at platinum electrodes. Part 1. An adsorption-controlled mechanism , 1998 .

[9]  Mu Shaolin,et al.  Bioelectrochemical responses of the polyaniline uricase electrode , 1992 .

[10]  Antonio Guerrieri,et al.  Electrosynthesized Bilayer Polymeric Membrane for Effective Elimination of Electroactive Interferents in Amperometric Biosensors , 1995 .

[11]  Sándor Szatmári,et al.  High-brightness ultraviolet excimer lasers , 1994 .

[12]  P. Bartlett,et al.  Conducting polymer gas sensors part I: fabrication and characterization , 1989 .

[13]  Wilfried Mokwa,et al.  Multianalyte sensor for the simultaneous determination of glucose, L-lactate and uric acid based on a microelectrode array , 1997 .

[14]  Mu Shaolin.  The kinetics of activated uricase immobilized on a polypyrrole film , 1994 .

[15]  Sándor Szatmári,et al.  Simplified laser system for the generation of 60 fs pulses at 248 nm , 1988 .